KING, Circuit Judge:
Plaintiff-Appellant Natasha Whitley appeals the dismissal of her 42 U.S.C. § 1983 action and the denial of her motion to amend her complaint. Whitley’s claims arise out of former City of Brownwood police sergeant Vincent Ariaz’s sexual abuse of her. Defendants-Appellees John Hanna, Robert Bullock, Michael Murray, [635]*635and Robert Grubbs were state officers involved in the investigation and arrest of Ariaz. Whitley argues that Appellees failed adequately to protect her from Ariaz, and used her as “sexual bait” to strengthen their prosecutorial case against him. The district court granted Appellees’ motions to dismiss after finding that Whitley failed to state a § 1988 claim and that Appellees would be entitled to qualified immunity. It also denied Whitley’s motion to amend her complaint. For the following reasons, we AFFIRM the district court’s judgment.
I. FACTUAL AND PROCEDURAL BACKGROUND
In 2000, the City of Brownwood created Explorer Post 1150 as part of the “Explorers” program — a school- and work-based program to introduce young people to various vocations. Explorer Post 1150 was established to teach participants about law enforcement, including police training and operations. Vincent Ariaz, a then-sergeant with the City of Brownwood Police Department, acted as Explorer Post 1150’s advisor. In January 2007, Ariaz was investigated for alleged abuse of one of the program’s female participants (“A.M.”). A Brownwood police officer, together with appellee Texas Ranger John Hanna, conducted the investigation.
Hanna interviewed A.M., and learned that Ariaz would use her as an example for activities like handcuffing and have her stay late when no one else was around. Hanna also discovered from A.M. that Ariaz would rub his body against hers and ask her about her sexual experiences. A.M. further informed Hanna of an incident in which she and Ariaz were alone in a storeroom. Ariaz allegedly closed the door, turned off the lights, and proceeded to kiss A.M. and fondle her breasts. Despite AM. telling him to stop, Ariaz continued until she was able to make noise and escape. AM.’s mother and her then-boyfriend also told Hanna that Ariaz had sent AM. numerous sexually suggestive text messages, including proposing having sex in a motel room. The boyfriend also lodged a complaint against Ariaz, to no apparent effect. An affidavit by another police officer stated that Ariaz had expressed a desire to engage in different sexual acts with a young girl.
Whitley’s allegations do not disclose what action, if any, the City of Brownwood or the Brownwood Police Department took in response to Hanna’s investigation or Ariaz’s conduct. We do know that Ariaz continued as a police officer for the City of Brownwood. Hanna, following his investigation, notified his lieutenant, appellee Robert Bullock, that he had obtained a “written statement detailing a pattern of sexual harassment, text messages of [a] sexual nature, and one incident of sexual contact.” The report was approved by Bullock on February 19, 2007, and stated that the investigation “would remain active.”
Sometime thereafter, Ariaz’s attention shifted to another Explorers participant— fifteen-year-old appellant Natasha Whitley. Ariaz began “grooming” Whitley by giving her gifts, promoting her to the highest position in the Explorer post, repeatedly using her as his example in class, and writing her love notes that she kept in her Explorers locker. Ariaz’s advances grew progressively more intimate and eventually became sexual around June 2007.
Although various individuals were aware that Ariaz was engaging in suspicious conduct, it does not appear that Hanna learned of this until July 3, when another member of the Brownwood Police Department, Richard Williams, noticed Whitley driving Ariaz’s truck and questioned her. In the course of speaking with her, Williams learned that Ariaz and Whitley drove together on a nightly basis. [636]*636Williams thereupon contacted Hanna, who resumed his investigation and quickly confirmed that Ariaz allowed Whitley to drive his vehicle, rode with her almost every night, and spent hours with her parked in locations that were secluded or known “make out” areas.
On July 9, Hanna met with the Brown County District Attorney, appellee Michael Murray, and the Brown County Sheriff, appellee Bobby Grubbs. Also present were Brown County’s Assistant District Attorney, a District Attorney investigator, the Brown County Chief Deputy, a sergeant with the Texas Department of Public Safety, a Brownwood police sergeant, and members of the West Central Interlocal Drug Task Force. The group discussed Hanna’s investigation into Ariaz’s conduct and agreed that Hanna would continue monitoring Ariaz to catch Ariaz in the act of abusing Whitley, and thus strengthen the prosecutorial case against him. Bullock endorsed the plan after Hanna informed him of the July 9 meeting.
Hanna proceeded to install video surveillance cameras in the hallways of the Brownwood Annex building — one of the locations Ariaz was known to take Whitley. Hanna also initiated GPS surveillance of Ariaz’s car. On July 10 and 11, Ariaz was observed with Whitley in the Annex building. Ariaz repeatedly hugged and kissed Whitley. Ariaz also was observed entering an Annex building courtroom where Whitley was waiting, and later exiting without his belt, followed by Whitley, who emerged adjusting her shirt. Ariaz and Whitley were known to spend lengthy periods of time in the Annex building courtroom. Hanna informed Bullock, Murray, and Grubbs of these events.
On July 12, Hanna assembled three two-man teams to surveil Ariaz and Whitley. Over the following days, Ariaz and Whitley repeatedly were observed engaging in the previously documented conduct. On July 17, Hanna and another investigator hid themselves in the closet of the courtroom Ariaz and Whitley previously had entered. Sometime after 2:30 a.m., Hanna witnessed Whitley sitting or lying on a table with Ariaz positioned over her. Ariaz and Whitley then left, but returned at 6:13 a.m. Whitley lay down, and Ariaz proceeded to kiss her for several minutes. He then placed his head in Whitley’s “crotch area,” whereupon Hanna exited the closet and intervened. Ariaz was arrested and indicted on more than twenty-five counts of sexual assault of a child and two counts of indecency with a child.1 He ultimately pleaded guilty to two counts of sexual assault of a child and no contest to indecency with a child. Ariaz currently is serving a twenty-year prison sentence.
On November 3, 2008, Whitley’s parents filed suit in federal district court against, among others, the City of Brownwood, the Brownwood Police Department, the Brownwood Chief of Police, and the Boy Scouts of America, in an action styled Whitley v. Ariaz, et al., No. 6:08-CV-85-C. That lawsuit was dismissed upon settlement.
On August 19, 2011, Whitley herself filed suit against Hanna and Bullock, in their individual capacities, and against Murray and Grubbs in their individual and official capacities (collectively, “Appellees”). Whitley also sought declaratory and injunctive relief against Appellees in their official capacities. Her complaint primarily contended that Appellees violated her constitutional rights by failing timely to intervene to stop Ariaz’s abuse of her.
[637]*637Murray and Grubbs filed a motion to dismiss for failure to state a claim under Federal Rule of Civil Procedure 12(b)(6) on September 13. On the same day, Hanna and Bullock filed a separate motion to dismiss for failure to state a claim under Rule 12(b)(6), in which they asserted qualified immunity. Subsequently, Murray and Grubbs filed an original answer in which they also raised a qualified immunity defense. Following the filing of Appellees’ motions to dismiss, Whitley filed a motion to amend her complaint.
In an order entered on February 21, 2012, the district court granted both motions to dismiss and denied Whitley’s motion to amend her complaint. The district court began by reviewing the proposed amended complaint and concluded that the amendments were “nothing more than reiterations of the original § 1983 claim premised upon substantive due process rights.” The court viewed the proposed amendments only as alleging that Appellees engaged in a conspiracy to deprive Whitley of her constitutional rights, a claim that was not actionable under § 1983 without an underlying constitutional violation. Further, it found that “the proposed additional facts that [Whitley] wishes to add to her pleadings do nothing to change the claims brought by [her].” Accordingly, the district court held that granting Whitley’s motion to amend her complaint would be futile and denied her motion.
Turning to Appellees’ motions to dismiss, the district court found that dismissal was warranted. “At the heart of the allegations is [Whitley’s] claim that the [Appellees] should have concluded their investigation sooner and arrested Ariaz sooner, thus preventing further sexual acts against her.” The court determined that Whitley’s § 1983 claims failed because there was no constitutional right to have criminal charges filed against someone or to have that person investigated.
The district court likewise was unpersuaded by what it construed as Whitley’s attempts to establish supervisory liability over Appellees. First, to the extent Appellees were involved in Ariaz’s misconduct, the district court found that they actively were investigating him and thus their behavior did not fall within the purview of cases that permitted claims against state actors who failed to protect victims from harm. Second, the district court noted that Appellees did not supervise Ariaz and actually were employed by completely separate entities. Properly construed, the district court reasoned, Whitley’s allegations really fell under a “state-created-danger theory,” because Appellees — as state actors — allegedly acted with deliberate indifference in creating or increasing a danger to her. But such a theory also requires that the state actors create an opportunity that otherwise would not have existed, which the district court found was not the case. Further, it noted that this circuit has declined to adopt a state-created-danger theory to trigger affirmative duties under the Due Process Clause. The district court thus granted Appellees’ motions to dismiss.
Whitley timely filed a notice of appeal on March 15, 2012, asserting that the district court erroneously granted Appellees’ motions to dismiss her § 1983 claims and denied her motion to amend her complaint.
II. STANDARD OF REVIEW
This court reviews a district court’s grant of a motion to dismiss de novo. Bowlby v. City of Aberdeen, Miss., 681 F.3d 215, 219 (5th Cir.2012). The grant of a motion to dismiss based on qualified immunity similarly is reviewed de novo. Brown v. Miller, 519 F.3d 231, 236 (5th Cir.2008). We accept all well-pleaded facts as true and view those facts in the light most favorable to the plaintiff. Bowlby, 681 F.3d at 219 (citation omitted). The [638]*638facts taken as true must, however, “state a claim that is plausible on its face.” Amacker v. Renaissance Asset Mgmt. LLC, 657 F.3d 252, 254 (5th Cir.2011). “A claim has facial plausibility when the plaintiff pleads factual content that allows the court to draw the reasonable inference that the defendant is liable for the misconduct alleged.” Ashcroft v. Iqbal, 556 U.S. 662, 678, 129 S.Ct. 1937, 173 L.Ed.2d 868 (2009). A complaint is insufficient if it offers only “labels and conclusions,” or “a formulaic recitation of the elements of a cause of action.” Id. (quoting Bell Atl. Corp. v. Twombly, 550 U.S. 544, 555, 127 S.Ct. 1955, 167 L.Ed.2d 929 (2007)).
We review a district court’s denial of a motion for leave to file an amended complaint for abuse of discretion. City of Clinton, Ark. v. Pilgrim’s Pride Corp., 632 F.3d 148, 152 (5th Cir.2010). However, where a district court’s denial solely was based on futility, this court applies a de novo standard identical, in practice, to the standard used for reviewing a motion to dismiss for failure to state a claim. See Wilson v. Bruks-Klockner, Inc., 602 F.3d 363, 368 (5th Cir.2010).
III. APPLICABLE LAW
A. Section 1983
Section 1983 provides a claim against anyone who “under color of any statute, ordinance, regulation, custom, or usage, of any State” violates another’s constitutional rights. 42 U.S.C. § 1983. “To state a section 1983 claim, ‘a plaintiff must (1) allege a violation of a right secured by the Constitution or laws of the United States and (2) demonstrate that the alleged deprivation was committed by a person acting under color of state law.’” James v. Tex. Collin Cnty., 535 F.3d 365, 373 (5th Cir.2008) (quoting Moore v. Willis Indep. Sch. Dist., 233 F.3d 871, 874 (5th Cir.2000)).
B. Qualified Immunity
“The doctrine of qualified immunity protects government officials from civil damages liability when their actions could reasonably have been believed to be legal.” Morgan v. Swanson, 659 F.3d 359, 370 (5th Cir.2011) (en banc). Qualified immunity protects “all but the plainly incompetent or those who knowingly violate the law,” Malley v. Briggs, 475 U.S. 335, 341, 106 S.Ct. 1092, 89 L.Ed.2d 271 (1986), and courts will not deny immunity unless “existing precedent ... placed the statutory or constitutional question beyond debate,” Ashcroft v. al-Kidd, — U.S.-, 131 S.Ct. 2074, 2083, 179 L.Ed.2d 1149 (2011). Therefore, a plaintiff seeking to overcome qualified immunity must show: “(1) that the official violated a statutory or constitutional right, and (2) that the right was ‘clearly established’ at the time of the challenged conduct.” Id. at 2080 (citation omitted). A court has discretion to decide which prong to consider first. Pearson v. Callahan, 555 U.S. 223, 236, 129 S.Ct. 808, 172 L.Ed.2d 565 (2009).
IV. DISCUSSION
On appeal, Whitley presents two theories of liability she asserts warrant reversal of the district court’s decision. First, relying on our decision in Doe v. Taylor Independent School District, 15 F.3d 443 (5th Cir.1994) (en banc), Whitley argues that Appellees are liable under § 1983 for acting with deliberate indifference to her constitutional rights by engaging in an investigation premised on catching Ariaz (the primary constitutional wrongdoer) in the act of abusing her. Second, citing to Hale v. Townley, 45 F.3d 914 (5th Cir.1995), Whitley asserts that Appellees are liable under § 1983 under a theory of bystander liability because they failed to stop Ariaz, a fellow officer, from violating Whitley’s fundamental liberty interest in her bodily integrity.2 Lastly, Whitley con[639]*639tends that the district court erred in denying her motion to amend her complaint.
We address each of her theories below, and conclude that Whitley fails to state a claim under either her deliberate indifference or bystander liability theory.3 Our conclusion that Whitley fails to state a claim as to any of the Appellees also resolves the question of qualified immunity raised in Hanna and Bullock’s motion to dismiss.4 See Lytle v. Bexar Cnty., Tex., 560 F.3d 404, 410 (5th Cir.2009) (“If we determine that the alleged conduct did not violate a constitutional right, our inquiry ceases because there is no constitutional violation for which the government official would need qualified immunity.”); Hampton v. Oktibbeha Cnty. Sheriff Dep’t, 480 F.3d 358, 363 (5th Cir.2007). Finally, we hold that the district court correctly denied Whitley’s motion to amend her complaint.
A. Deliberate Indifference
Whitley’s first basis for establishing liability under § 1983 is “the decision by [Appellees] as part of their investigation, to knowingly allow Whitley to be repeatedly raped by another police officer.” Put another way, Appellees purportedly acted with deliberate indifference by agreeing on a plan that would allow Ariaz to continue sexually abusing Whitley for the sake of gathering additional evidence to secure his conviction.5 In support, Whitley primarily [640]*640relies on our decision in Taylor, 15 F.3d 443.6
In Taylor, we considered whether a school’s principal and the district’s superintendent could be held liable under § 1983 for failing to prevent a high school coach from manipulating a fifteen-year-old student over several months into repeatedly having sexual intercourse with him. Id. at 446-49. In affirming the district court’s denial of qualified immunity to the principal, but reversing the denial of qualified immunity to the superintendent, we held that:
A supervisory school official can be held personally liable for a subordinate’s violation of an elementary or secondary school student’s constitutional right to bodily integrity in physical sexual abuse cases if the plaintiff establishes that:
(1) the defendant learned of facts or a pattern of inappropriate sexual behavior by a subordinate pointing plainly toward the conclusion that the subordinate was sexually abusing the student; and
(2) the defendant demonstrated deliberate indifference toward the constitutional rights of the student by failing to take action that was obviously necessary to prevent or stop the abuse; and
(3) such failure caused a constitutional injury to the student.
Taylor, 15 F.3d at 454.
Subsequently, in Doe v. Rains County Independent School District, 66 F.3d 1402 (5th Cir.1995), we expanded our holding in Taylor to include non-supervisory state officers. We determined that “once ... a constitutional violation has occurred, we are no longer barred from finding another person liable under § 1983 for committing a state-law breach that caused the constitutional injury, even if the breach itself does not independently satisfy the elements of a constitutional claim.” Id. at 1409. We reached this conclusion by “ask[ing] what it is about a supervisor’s duties and functions that renders a state supervisory official hable for a constitutional deprivation by a subordinate.” Id. at 1410. We concluded that “it is state law’s grant of a right of legal control over the immediate perpetrator of an injury that establishes that a state supervisor possessed and exercised state authority.” Id. at 1413. The “critical question” in determining whether a non-supervisory state actor may be held liable thus is “whether state law has reposed in a defendant enough responsibility for the underlying conduct that she can be said to have caused the injury herself.” Id. at 1408.
Accordingly, Whitley must show that (1) Appellees knew of a pattern of constitutional deprivations; (2) the abuse was caused by a state actor over whom they had supervisory authority or a state-law created right of legal control; (3) Appellees’ failure to act demonstrated deliberate indifference to the victim’s constitutional rights; and (4) their failure to act resulted in a constitutional injury. Because we conclude that Appellees were not deliber[641]*641ately indifferent, we limit our analysis to the third element, and hold that Whitley’s § 1988 claims fail under her deliberate indifference theory.7
“The deliberate indifference standard is a high one.” Doe v. Dall. Indep. Sch. Dist., 158 F.3d 211, 219 (5th Cir.1998). “To act with deliberate indifference, a state actor must ‘know[] of and disregard! ] an excessive risk to [the victim’s] health or safety.’ ” McClendon, 305 F.3d at 326 n. 8 (alterations in original) (quoting Farmer v. Brennan, 511 U.S. 825, 837, 114 S.Ct. 1970, 128 L.Ed.2d 811 (1994)). “The state actor’s actual knowledge is critical to the inquiry” — a “failure to alleviate ‘a significant risk that he should have perceived but did not,’ while ‘no cause for commendation,’ does not rise to the level of deliberate indifference.” Id. (quoting Farmer, 511 U.S. at 837, 114 S.Ct. 1970). While we previously have observed that the terms “gross negligence” and “deliberate indifference” are sometimes used interchangeably, understood properly, “the former is a ‘heightened degree of negligence,’ [while] the latter is a ‘lesser form of intent.’ ” Taylor, 15 F.3d at 453 n. 7 (citation omitted).
In this case, the district court found that Appellees did not act with deliberate indifference because they were “acting on facts and investigating Ariaz.” Whitley contends that the district court’s finding was erroneous because Appellees’ investigation clearly was flawed, and identifies multiple indicators Appellees had that Ariaz — even before meeting Whitley — was engaging in sexual misconduct. Whitley also highlights purported deficiencies in the investigation itself.
We agree with the district court that neither Hanna and Bullock, nor Grubbs and Murray, were deliberately indifferent.
1. Hanna and Bullock
a) Hanna
We begin our analysis by considering Hanna’s investigation, which, while possibly subject to criticism and charges of deficiency, cannot be said to have been conducted with deliberate indifference. Hanna began investigating Ariaz in January 2007, and spoke with A.M., A.M.’s [642]*642mother, and her boyfriend. Although the investigation did not, at that time, result in the arrest and prosecution of Ariaz, the investigation remained open.
Over the next several months, there were numerous incidents indicating that Ariaz’s attention had shifted to a new victim — Whitley. Ariaz repeatedly used Wbitley as his example in class, and made her his Explorers captain. He also ate with Wbitley in view of other Brownwood Police Department officers. It apparently was well-known that Ariaz and Wbitley would ride together during the night shift. But while the Brownwood Police Department may have been aware of Ariaz’s conduct, Hanna was not. Hanna had no reason to think that the Brownwood Police Department, as Ariaz’s supervisor, would fail to respond to evidence that Ariaz again was targeting a minor, including sharing such evidence with Hanna.8
Hanna’s failure to discover Ariaz’s new relationship earlier thus is no ground for finding him deliberately indifferent. In Taylor, we found a school superintendent not deliberately indifferent partly because he reacted promptly to new evidence of a high school coach’s sexual misconduct. 15 F.3d at 457-58. Similarly here, when Hanna received word that Ariaz again was seen with a minor, he immediately resumed his investigation. From that point on, Hanna undertook a series of measures that appropriately responded to the evidence available to him, including:
• learning that Ariaz was riding with Wbitley almost every night, and allowing her to drive his vehicle;
• discovering that Ariaz, accompanied by Wbitley, would park for two to three hours in remote areas such as the Brownwood airport, a wooded area by the Brownwood Hospital, and an old police department;
• meeting with Murray, the Brown County District Attorney, and Grubbs, the Brown County Sheriff, and others to discuss Ariaz’s behavior;
• installing video surveillance cameras in the Brownwood Annex building, one of the isolated locations Ariaz was known to take Wbitley;
• placing GPS surveillance on Ariaz’s vehicle, despite Ariaz previously having requested vehicles without GPS tracking;
• assembling three two-man teams to surveil Ariaz and Wbitley;
• organizing a sting operation that resulted in the arrest and prosecution of Ariaz.
Wbereas Hanna’s previous investigation into Ariaz did not result in a prosecution, Hanna’s actions upon learning that Ariaz was seen with Wbitley demonstrate that, while the Brownwood Police Department apparently had been unable to stop Ariaz, Hanna was committed to putting an end to Ariaz’s abuses once and for all.
Wbitley criticizes various aspects of Hanna’s investigation, but these do not amount to a showing of deliberate indifference. She accuses Hanna of improperly placing surveillance cameras in the Brown-wood Annex building’s hallways, instead of in its courtroom. But the mere “haphazard” or “negligent” deployment of security measures does not establish deliberate indifference. Johnson v. Dall. Indep. Sch. Dist., 38 F.3d 198, 202 (5th Cir.1994). Wbitley also criticizes Hanna for conducting an excessively long investigation. Yet, in light of Ariaz’s persistent conduct, even in the face of other members of the Brownwood Police Department knowing of the suspicious activity, we cannot fault Hanna for wanting to ensure that this time [643]*643the investigation would conclude with Ariaz’s successful prosecution. At most, Whitley has shown that Hanna’s actions were comparable to those of Taylor’s superintendent. After observing that the superintendent had directed the principal to talk with the coach suspected of sexual abuse, contacted parents, spoken with the victim, and verbally reprimanded the coach, we determined that although the superintendent’s actions had been “ineffective,” they were not “deliberately indifferent.” 15 F.3d at 457-58. As in that case, although we do not deny the possibility that Hanna could have conducted the investigation differently, perhaps even gathering enough evidence to make an arrest in less than the two weeks it took him, Hanna’s failure to immediately end the abuse does not make him deliberately indifferent. See Dall. Indep. Sch. Dist., 153 F.3d at 219 (“Actions and decisions by officials that are merely inept, erroneous, ineffective, or negligent do not amount to deliberate indifference and thus do not divest the official of qualified immunity.”).9
Hanna had to decide what evidence would suffice to secure a conviction. His decision to wait two or three days longer to make a stronger ease to permanently stop Ariaz’s misconduct does not bring this case within Taylor’s fact pattern, where we denied qualified immunity to a school principal on the ground that he “fail[ed] to take action that was obviously necessary to prevent or stop” the sexual misconduct of a subordinate high school coach. 15 F.3d at 457. Far from failing to take action, Hanna led an ongoing effort to put Ariaz out of business. In this, Hanna was successful. His failure to be successful earlier does not make him deliberately indifferent to Whitley’s plight.
Whitley also appears, however, to allege that Hanna was deliberately indifferent because he failed to intervene when Ariaz sexually abused her in Hanna’s presence. This argument refers to Hanna’s failure immediately to emerge from his courtroom hiding place upon witnessing Ariaz positioned atop her the morning of July 17, 2007. We find it worthwhile to quote this part of Whitley’s complaint in its entirety:
• At approximately 2:30 a.m. on July 17, 2007, Hanna hid in the courtroom’s closet with another investigator.
• He observed [Whitley] sitting or lying on a table with Ariaz positioned over her in a clearly inappropriate and sexual manner.
• Yet Hanna still did not intervene.
[644]*644• Instead, he let Ariaz continue and then let them leave.
• According to Hanna, he remained at the Annex so that he would be more ready the next time to catch Ariaz in the midst of a more prolonged act.
• Then, according to Hanna, Ariaz and [Whitley] arrived back at the Annex at 6:13 a.m. Ariaz began kissing [Whitley] in the courtroom for several minutes while [Whitley] was lying down. Then, Hanna observed him place his head in [Whitley’s] “crotch area.”
Whitley’s proposed amended complaint, which we separately address infra, elaborates only slightly on these facts: “[Hanna] observed Plaintiff sitting or lying on a table with Ariaz positioned over her in a clearly inappropriate and sexual manner. Ariaz was touching Plaintiffs genitalia.” Hanna ultimately emerged and arrested Ariaz when he observed Ariaz placing his head in Whitley’s genital area after the two returned at 6:13 a.m.
Several aspects of Whitley’s complaint, as well as the relevant parts of her proposed amended complaint, draw our attention. Although Whitley’s brief repeatedly describes Appellees as exposing Whitley to statutory rape (even going so far as accusing them of effectively raping Whitley herself by failing to act), the closest Hanna came to actually seeing Ariaz sexually abuse Whitley was to observe her sitting or lying while Ariaz was positioned over her. Whitley does not describe what Ariaz was doing other than to say it was “clearly inappropriate” and done in a “sexual manner.” Additionally, while specifically describing what Hanna observed in every part of her complaint, Whitley noticeably omits in her proposed amended complaint whether or not Hanna observed Ariaz touching her genitals.10 Hanna apparently could not even see whether Whitley was sitting or lying down.
While we must view the facts in the light most favorable to Whitley, we also cannot ignore what she has, and has not, pled. Nor can we ignore that Hanna, after tracking Ariaz by camera, GPS, and officer surveillance, emerged from cover to arrest Ariaz after observing him engage in a clearly sexual act. Whitley may have alleged facts sufficient to show that Hanna made an error of judgment, but we refuse to find that Hanna’s failure to act, after viewing some unspecified conduct that was “clearly inappropriate,” transformed his otherwise proper investigation into one that was deliberately indifferent. See Callis v. Sellars, 931 F.Supp. 504, 519 (S.D.Tex.1996) (officers’ failure to timely intervene in sting operation amounted to isolated instance of negligence or error of judgment that did not amount to deliberate indifference).
Whitley thus has failed to allege facts sufficient to show that Hanna was deliberately indifferent.
b) Bullock
Having found that Hanna did not act deliberately indifferent, we similarly conclude that Whitley has not demonstrated that Bullock was deliberately indifferent in entrusting the investigation to Hanna. As with Hanna, the Brownwood Police Department’s failure to notify the Texas Rangers of Ariaz’s renewed involvement with a minor cannot be imputed to Bullock. Indeed, Bullock’s involvement in the investigation was limited to receiving updates from Hanna on how the investigation was progressing, and approving Hanna’s continuation of that investigation. Bullock was not even involved in the meeting in which Hanna, Murray, and Grubbs dis[645]*645cussed Ariaz, and which resulted in the decision to continue surveilling Ariaz until there was actual evidence of sexual abuse. Whitley has alleged no facts suggesting that Bullock knew Hanna was acting improperly in seeking to collect additional evidence, especially as the prior investigation into Ariaz’s conduct towards A.M. had not resulted in a prosecution. Whitley thus also has failed to show that Bullock was deliberately indifferent.
2. Grubbs and Murray
Whitley’s primary reason for claiming Grubbs and Murray acted with deliberate indifference is that they participated in formulating, and endorsed, a plan dependent on catching Ariaz in the act of committing an act of sexual abuse. However, far from being the product of deliberate indifference, this plan was responsive to the requirements of the Texas penal code. Ariaz eventually was charged with sexual assault of a child and indecency with a child. Under Texas law, the crime of sexual assault requires sexual contact or penetration. Tex. Penal Code Ann. § 22.011(a)(l)-(2). Similarly, the offense of indecency with a child requires exposure or “sexual contact,” defined as “(1) any touching by a person, including touching through clothing, of the anus, breast, or any part of the genitals of a child; or (2) any touching of any part of the body of a child, including touching through clothing, with the anus, breast, or any part of the genitals of a person.” Id. § 21.11. Video evidence only showed Ariaz hugging and kissing Whitley, actions which Appellees could not be certain a jury would find sufficient to violate the applicable criminal statutes. As Whitley acknowledges, Appellees only “had video proof that [Whitley] was likely being abused.”
Grubbs and Murray also did not ignore Whitley’s plight — to the contrary, they agreed that Hanna would investigate allegations of Ariaz’s sexual misconduct in order to prosecute Ariaz. They were aware that Hanna was pursuing the investigation by setting up surveillance cameras, tracking Ariaz’s movements, and devoting three two-man teams to surveilling him. Moreover, Grubbs and Murray were not telling Hanna to allow Ariaz to abuse Whitley, but rather to gather evidence and stop Ariaz from doing so. Although Whitley alleges that, based on the evidence available to them, Grubbs and Murray must have known that Ariaz was sexually abusing her, there is no allegation that they actively facilitated Ariaz’s behavior in order to gather more evidence.
Accordingly, although the decision to gather additional evidence may have been imprudent in light of that already available, we cannot say that Grubbs and Murray were deliberately indifferent to Whitley’s peril. It is unclear, for example, what they should have done that was any more certain to safeguard Whitley’s well-being or result in a favorable outcome to the investigation. They did not supervise Ariaz. They also did not have the authority to order the Brownwood Police Department to remove Ariaz from duty. At oral argument, Whitley’s counsel admitted that Appellees, including Grubbs and Murray, also lacked the power to end the Explorers program. Further, while Grubbs and Murray arguably had the power to effectuate the arrest of Ariaz earlier in the investigation, Whitley has made clear that she is not premising her claim on Appellees’ arresting Ariaz. Thus, although we easily can imagine some alternatives to the choice that Appellees made — including confronting Whitley or contacting her parents — the fact remains that Appellees successfully brought about Ariaz’s arrest approximately two weeks after Hanna first learned of a potential relationship between Ariaz and Whitley.
We conclude that Whitley has not alleged facts sufficient to establish that [646]*646Grubbs and Murray acted with deliberate indifference.
B. Bystander Liability
Whitley’s second basis for establishing liability under § 1983 is Appellees’ “failure ... to attempt to intercede to protect [her] from further abuse at the hands of another officer.” Whitley cites this court’s decision in Hale, 45 F.3d 914, for the proposition that Appellees were required to intervene and stop Ariaz from further sexually abusing her.
In Hale, a plaintiff brought a § 1983 action for, inter alia, the use of excessive force during a search and arrest. Id. at 916. One of the police officer defendants allegedly stood by, laughed, and shouted encouragement while another officer assaulted the plaintiff. Id. at 919. Characterizing the plaintiffs claim as one of bystander liability, this court agreed that “an officer who is present at the scene and does not take reasonable measures to protect a suspect from another officer’s use of excessive force may be liable under section 1983.” Id. We further observed that the fact that the police officers “were from different law enforcement agencies does not as a matter of law relieve [an officer] from liability for a failure to intervene.” Id. In light of the allegations and evidence in that case, we concluded that there was sufficient evidence to create a genuine issue of material fact concerning the by-standing officer’s “acquiescence in the alleged use of excessive force.” Id.
Our holding in Hale is consistent with other circuits’ determination that an officer may be liable under § 1983 under a theory of bystander liability where the officer “(1) knows that a fellow officer is violating an individual’s constitutional rights; (2) has a reasonable opportunity to prevent the harm; and (3) chooses not to act.” 11 Randall v. Prince George’s Cnty., Md., 302 F.3d 188, 204 (4th Cir.2002) (footnote omitted); see, e.g., Lewis v. Downey, 581 F.3d 467, 472 (7th Cir.2009); Smith v. Mensinger, 293 F.3d 641, 650-51 (3d Cir.2002); see also Nowell v. Acadian Ambulance Serv., 147 F.Supp.2d 495, 507 (W.D.La.2001). However, liability will not attach where an officer is not present at the scene of the constitutional violation.12 See Snyder v. Trepagnier, 142 F.3d 791, [647]*647801 n. 11 (5th Cir.1998) (citing Hale, 45 F.3d at 919); see also Gilbert v. French, 364 Fed.Appx. 76, 83 (5th Cir.2010) (per curiam) (unpublished); Ibarra v. Harris Cnty. Tex., 243 Fed.Appx. 830, 835 & n. 8 (5th Cir.2007) (per curiam) (unpublished) (“A bystander liability claim requires the plaintiffs to show that the officer was present at the scene and did not take reasonable measures to protect a suspect from excessive force.”). In resolving whether a plaintiff has sufficiently alleged a bystander liability claim we also consider whether an officer “aequiesce[d] in” the alleged constitutional violation. Hale, 45 F.3d at 919; see Baker v. Monroe Twp., 50 F.3d 1186, 1193-94 (3d Cir.1995) (premising liability on senior officer’s knowledge of, and acquiescence in, treatment of victim); see also Peary v. Dali. Indep. Sch. Dist., 57 F.Supp.2d 382, 390 n. 4 (N.D.Tex.1999) (Hale inapplicable where defendant did not acquiesce in any conduct violating plaintiffs constitutional rights).
Applying this analysis to each of the Appellees, Whitley has failed to state a claim of bystander liability.
We observe at the outset that Whitley has failed to state a claim against Bullock because she has not alleged that he was in Ariaz’s presence when Ariaz was sexually abusing Whitley. As a result, Bullock is not within the scope of a bystander liability claim. See Hale, 45 F.3d at 919; Ibarra, 243 Fed.Appx. at 835 & n. 8. Even were we merely to require knowledge, Bullock still would not be liable because he acted reasonably in entrusting Hanna with investigating and arresting Ariaz.
Turning to Hanna, although Whitley has alleged that Hanna was in Ariaz’s presence (unbeknownst to Ariaz) the morning of July 17, she nevertheless has failed to state a claim because she has not alleged that Hanna acquiesced in Ariaz’s conduct. Hanna was investigating Ariaz with the intent of gathering evidence to secure Ariaz’s conviction for sexual abuse of a minor. Far from being a bystander to Ariaz’s conduct, Hanna was accumulating evidence for Ariaz’s prosecution. This is in no way comparable to the factual scenario in Hale, where there was a genuine dispute over whether an officer’s laughing and shouting encouragement to another officer who was committing a constitutional violation constituted acquiescence in the latter’s conduct. Hanna’s subsequent arrest of Ariaz after Ariaz began to engage in a clearly sexual act dispels all doubt as to whether Hanna acquiesced in Ariaz’s misconduct. Cf. Randall, 302 F.3d at 204 n. 24 (“The rationale underlying the bystander liability theory is that a bystanding officer, by choosing not to intervene, functionally participates in the unconstitutional act of his fellow officer.”).
Accordingly, we reject Whitley’s bystander liability claims against Hanna and Bullock.13
[648]*6482. Grubbs and Murray
Like Bullock, neither Grubbs nor Murray was in Ariaz’s presence during Ariaz’s abusive conduct. They thus also are not bystanders for purposes of a bystander liability claim. See Hale, 45 F.3d at 919; Ibarra, 243 Fed.Appx. at 835 & n. 8. Further, they acted reasonably in attempting to stop Ariaz from further abusing Whitley and other minors by endorsing a plan that would lead to the arrest of Ariaz. As discussed supra, it is unclear exactly what other actions Whitley would have required from Grubbs and Murray that were more certain to permanently remove her and others from Ariaz’s reach.
For these reasons, we reject Whitley’s bystander liability claims as to Grubbs and Murray.
C. Motion to Amend the Complaint
Rule 15 of the Federal Rules of Civil Procedure provides that leave to amend should be freely given “when justice so requires.” Fed.R.Civ.P. 15(a)(2). A motion to amend ordinarily should be granted absent some justification for refusal. Foman v. Davis, 371 U.S. 178, 182, 83 S.Ct. 227, 9 L.Ed.2d 222 (1962).
The liberal amendment policy underlying Rule 15(a) affords the court broad discretion in granting leave to amend and, consequently, a motion for leave to amend should not be denied unless there is “undue delay, bad faith or dilatory motive on the part of the movant, repeated failure to cure deficiencies by amendments previously allowed [or] undue prejudice to the opposing party by virtue of allowance of the amendment,
United States ex rel. Willard v. Humana Health Plan of Tex. Inc., 336 F.3d 375, 386 (5th Cir.2003) (alteration in original) (citation omitted). Leave to amend also may be denied when amendment would be futile. Id. at 387.
We find that, even under Rule 15’s liberal standard, the district court appropriately denied as futile Whitley’s motion to amend her complaint. First, the amended complaint adds no new substantive factual allegations. As already discussed, even if we read her complaint to allege that Hanna witnessed Ariaz sexually abusing Whitley, liability would not extend to Hanna— nor the other Appellees because Hanna was not deliberately indifferent and did not acquiesce in Ariaz’s conduct.
Second, the amended complaint’s new causes of action are meritless. Whitley adds supervisory liability claims, including for inadequate supervision and failure to train. She also adds policy, custom, and practice claims, alleging, inter alia, that it was “the practice of the Texas Rangers to permit minor sexual assault victims to be used as bait to catch their assailants.” Finally, the amended complaint adds a series of “Secondary Liability Claims” including “Assisting and Encouraging / Aiding and Abetting sexual abuse and invasions of bodily integrity,” “Assisting and Participating in violations of bodily integrity and sexual abuse,” and “Conspiracy to violate Plaintiffs right to be free from violations of her bodily integrity and ... sexual abuse,” all in violation of § 1983.
All of Whitley’s inadequate supervision, failure to train, and policy, practice, or custom claims fail without an underlying constitutional violation. See Bustos v. [649]*649Martini Chib, Inc., 599 F.Sd 458, 467 (5th Cir.2010) (“Because [plaintiff] has alleged no constitutional injury attributable to the Officers, [plaintiff] has failed to state a claim that a City policy was the moving force behind a violation of his constitutional rights.”). Even if we assume that Whitley has sufficiently alleged a § 1983 claim, her municipal liability claims still would fail. “To establish municipal liability under § 1983, a plaintiff must show that (1) an official policy (2) promulgated by the municipal policymaker (3) was the moving force behind the violation of a constitutional right.” Peterson v. City of Fort Worth, Tex., 588 F.3d 838, 847 (5th Cir.2009). The proposed amended complaint makes no specific factual allegations of the county’s policies and simply adds the words “policies, practices, and/or customs” to Whitley’s perceived wrongs. Such allegations are insufficient to survive dismissal. See Spiller v. City of Tex. City, Police Dep’t, 130 F.3d 162, 167 (5th Cir.1997) (conclusory description of policy or custom insufficient).
Her secondary liability claims similarly fail for lack of a § 1983 violation by Appellees. See Hale, 45 F.3d at 920 (“[A] conspiracy claim is not actionable without an actual violation of section 1983.” (internal quotation marks and citation omitted)). Additionally, her aiding and abetting, assisting and participating, and conspiracy claims merely restate her § 1983 allegations. For the same reasons we are unpersuaded by her § 1983 claims, we also reject her secondary liability claims.
We agree with the district court that amendment of her complaint would be futile and that Whitley’s motion to amend correctly was denied.
V. CONCLUSION
For the aforementioned reasons, the district court’s judgment is AFFIRMED.