BETTY B. FLETCHER, Circuit Judge:
Darla Motley brings this 42 U.S.C. § 1983 action on behalf of herself and her infant son Juan Jamerson, claiming that the defendants unlawfully searched her home and used excessive force against her infant son. The defendants-appellees are Albert Ruegg, Gregory Kading, Daryl Gates, and Bernard Parks of the Los An-geles Police Department (LAPD); Guadalupe Sanchez, a California Parole Officer; and James Black and Larry Webster, who are federal Bureau of Alcohol, Tobacco, and Firearms (ATF) agents (collectively, “the officers”). The officers claim qualified immunity for their actions, and Motley appeals from two district court orders granting summary judgment on that basis. We reverse the district court’s grant of [1061] qualified immunity to Ruegg, Sanchez, Kading, and Black on the search and excessive force claims. We affirm the grant of summary judgment to Webster, Gates, and Parks.
FACTS AND PROCEDURAL HISTORY
Janae Jamerson, a member of the Four Trey Crips gang, was released on parole on February 20, 1998, but was rearrested on February 3, 1999. On March 18, 1999, while Jamerson was in custody, LAPD supervisor Ruegg held a briefing for LAPD officers, federal ATF officers, and state parole officers regarding ten planned searches of parolees’ residences in the Newton Street area. Jamerson’s last known residence was on the list. The officers admit they had no reasonable suspicion to believe that Jamerson was involved in any crime; they were simply searching parolees as a way to “clean up” the Newton Street neighborhood.
The address information for the searches may have been compiled as early as November 1998, while the search took place in March 1999. Jamerson’s in-custody status was listed on the state parole system, and Jamerson’s parole officer knew he was in custody, but none of the officers assigned to conduct a parole search of Jamerson’s last known residence checked to see if he was in custody on March 18,1999.
At 10:00 or 10:30 that morning, four officers from the various agencies went to search what was allegedly Jamerson’s residence. James Black and Larry Webster, the two ATF officers, went behind the house, and Parole Officer Guadalupe Sanchez and LAPD officer Gregory Kading went to the front door. One of the officers knocked on the door, and awakened Motley, Jamerson’s girlfriend, who was asleep with their infant son, Juan Jamerson. Black joined Kading and Sanchez at the front of the house as soon as Motley answered the door.1
Motley testified that when she came to the door in her pajamas, Kading identified himself as an LAPD officer, said that he was there with Jamerson’s parole officer, and asserted that they had a warrant to search the apartment. In fact, the officers had no warrant, and Jamerson’s parole officer was neither present nor even aware of the planned search. Motley told the searching officers that Jamerson did not live there and that he was in custody.2 One of the officers told Motley that Jamer-son had been released three days earlier. Motley countered that she knew Jamerson was still in custody. The searching officers asked who was inside with her, and Motley replied that only she and her five-week-old son were at home. Kading told Motley that if she did not let them in, they would arrest her and put her baby in foster care. Once the searching officers threatened to place her son in foster care, Motley unlocked the security gate. Kad-ing pushed her against the door and out of his way as he went into the house.3
The searching officers went into the apartment with their guns drawn, and [1062] Sanchez, the parole officer, stayed in the living room while Kading and Black searched the apartment. Motley testified that during the search, the officers were “going through things,” including closets and a file box, and that they “pulled out” a lot of things.
Before the officers searched the bedrooms, Motley told the officers that her son was in the back bedroom. When Kad-ing entered this bedroom, he pointed his gun at Motley’s baby, who was on his back on the bed, looking toward the bedroom' door. When Motley heard her five-week-old son start screaming, she ran into the room, where Kading was still pointing the gun at the baby. According to Motley, Kading kept his gun trained on the baby while he searched the room, and only put his gun away when another officer came in and helped him examine a box at the foot of the bed. Motley testified that the search of this bedroom alone took twenty minutes.
During the officers’ search of the apartment, Motley called Rasheed Davis, Jam-erson’s brother, and told Davis that the officers had threatened her and were searching her home. She asked Davis to come over to help her, and he arrived as the searching officers were leaving.4
The officers appeared to be mocking Motley during the search. One of the officers asked to whom the baby belonged, and when Motley told them that Janae Jamerson was the baby’s father, the officers laughed at her. While searching one of the rooms, Kading asked where “that really nice ping pong table” was, as though he wanted to take Motley’s things. As the officers were leaving, Kading shouted that Motley should “let them know that Newton Street had been here.”
After the officers left, Motley called Jamerson’s parole officer, Ms. Smith, and told her that officers had come and searched her entire home. Ms. Smith stated that she did not authorize the search and confirmed that Jamerson was still in custody. A few weeks after the search of her residence, Motley moved to San Pedro, because she was afraid to stay in the Newton Street area with her son.
Motley, on behalf of herself and her son Juan, filed a § 1983 action alleging that the officers violated their Fourth Amendment rights, used excessive force, conspired to violate their Fourth Amendment and equal protection rights, and that the law enforcement agencies were liable for the officers’ actions under Monell v. Dep’t of Social Services, 436 U.S. 658, 98 S.Ct. 2018, 56 L.Ed.2d 611 (1978). The district court granted summary judgment on all claims. Motley argues on appeal that the officers were not entitled to qualified immunity for the unlawful search, the use of excessive force against her infant son, and the Monell claims against Gates and Parks.
ANALYSIS
We review de novo the district court’s decision regarding qualified immunity. Mena v. City of Simi Valley, 332 F.3d 1255, 1261 n. 2 (9th Cir.2003). Where material issues of fact are disputed, we “assume that the version of the facts asserted by the non-moving party is correct.” Bingham v. City of Manhattan Beach, 341 F.3d 939, 942 (9th Cir.2003); see also Schwenk v. Hartford, 204 F.3d 1187, 1193 n. 3 (9th Cir.2000).
To determine whether law enforcement officers are entitled to qualified immunity, we first ask whether, “[tjaken in the light most favorable to the party asserting the injury, ... the facts alleged show the officer’s conduct violated a con[1063] stitutional right.” Saucier v. Katz, 533 U.S. 194, 201, 121 S.Ct. 2151, 150 L.Ed.2d 272 (2001). If we determine that there is a constitutional violation, we then examine whether the constitutional right was clearly established, such that a reasonable officer would have been aware that he was acting unlawfully. Id. at 202, 121 S.Ct. 2151. Although the inquiry into what is “clearly established” must be decided with reference to the specific situation the officers confronted, “officials can still be on notice that their conduct violates established law even in novel factual circumstances.” Hope v. Pelzer, 536 U.S. 730, 741, 122 S.Ct. 2508, 153 L.Ed.2d 666 (2002) (noting that the Supreme Court has expressly rejected a requirement that the facts of previous cases be fundamentally or even materially similar).
I. Fourth Amendment Violation: Unconstitutional Search
“The Fourth Amendment’s touchstone is reasonableness, and the reasonableness of a search is determined by assessing, on the one hand, the degree to which it intrudes upon an individual’s privacy and, on the other, the degree to which it is needed for the promotion of legitimate governmental interests.” United States v. Knights, 534 U.S. 112, 118-19, 122 S.Ct. 587, 151 L.Ed.2d 497 (2001) (citing Wyoming v. Houghton, 526 U.S. 295, 300, 119 S.Ct. 1297, 143 L.Ed.2d 408 (1999)). As the Supreme Court recently reiterated: “Because the right of a man to retreat into his own home and there be free from unreasonable governmental intrusion stands at the very core of the Fourth Amendment, our cases have firmly established the basic principle of Fourth Amendment law that searches and seizures inside a home without a warrant are presumptively unreasonable.” Groh v. Ramirez, 540 U.S. 551, 124 S.Ct. 1284, 1291, 157 L.Ed.2d 1068 (2004) (internal quotation marks omitted) (quoting Kyllo v. United States, 533 U.S. 27, 31, 121 S.Ct. 2038, 150 L.Ed.2d 94 (2001) and Payton v. New York, 445 U.S. 573, 586, 100 S.Ct. 1371, 63 L.Ed.2d 639 (1980)).
The officers in this case set out to conduct a parole search. Instead, assuming that Motley’s account is true, the officers used duress to gain access to the home of an innocent mother and her baby and conducted a warrantless search in a harassing manner. It is clear that if no parolee lived at Motley’s residence at the time of the search, the search violated Motley’s Fourth Amendment right to be free from warrantless searches. Cf. Steagald v. United States, 451 U.S. 204, 213, 101 S.Ct. 1642, 68 L.Ed.2d 38 (1981) (holding that officers could not enter and search the house of a third party simply because they had a “reasonable ... belief’ that the subject of an arrest warrant was a guest there; they had to have evidence that he was a co-resident); Perez v. Simmons, 884 F.2d 1136, 1141 (9th Cir.1988) (“It may be true that if [the subject of an arrest warrant’s] Fourth Amendment rights were at issue, [his sister’s] apartment might be considered his ‘residence,’ even though it was a very temporary place of occupancy. But it simply does not follow that, when analyzing [his sister’s] constitutional rights, [her brother] must be considered a co-resident just because he spent the night there on occasion.”).
The less stringent Fourth Amendment requirements for a parole search are the only justification the officers here have offered for why this search was constitutional. However, Jamerson had been incarcerated for six weeks at the time of the search, and Motley testified that her apartment was no longer Jamerson’s residence. Without requiring a close temporal connection between a parolee and the residence to be searched, officers would have carte blanche to search, without probable cause, any place where a parolee used to [1064] live. Eventually, as in this case, these searches would not affect the incarcerated “parolee” at all, only violate the privacy of the people he left behind.
The dissent asserts that we previously have held constitutional parole searches that took place after the parolee was incarcerated, as though those cases support the constitutionality of the search of Motley’s home. However, in each of the cases he cites, the parole search took place the same day as the arrest, and the officers had at least reasonable suspicion that the parolee’s home contained contraband. United States v. Dally, 606 F.2d 861, 863 (9th Cir.1979) (upholding parole search where the parolee was arrested just outside the house and right afterward, the officers searched the house); Latta v. Fitzharris, 521 F.2d 246, 247 (9th Cir.1975) (upholding parole search where officers arrested parolee away from his residence with marijuana in his possession, then went to his house and found more marijuana); United States v. Jones, 152 F.3d 680, 683, 686-87 (7th Cir.1998) (upholding the search of a parolee’s home the day he was arrested because the officers had reasonable grounds to believe that cocaine and firearms were located inside). In Dally, Latta, and Jones, the parole searches were directly related to the arrest of the parolee. These holdings do not alter the fact that it is unconstitutional for officers to search a person’s home without a warrant simply because a parolee used to live there.
Finally, the purpose of allowing parole searches without a warrant is “to assure that the [parole] serves as a period of genuine rehabilitation and that the community is not harmed by the [parolee’s] being at large.” Griffin v. Wisconsin, 483 U.S. 868, 875, 107 S.Ct. 3164, 97 L.Ed.2d 709 (1987). When the parolee is no longer “at large” and the search no longer affects his interests, both of these justifications are absent. Construing the facts in her favor, Motley has established that the officers violated her Fourth Amendment right to be free of warrantless searches.
II. Violation of Clearly Established Law: Unconstitutional Search
The officers assert that because they reasonably believed they were conducting a parole search of Jamerson’s residence, they are entitled to qualified immunity. It is true that a parolee subject to a search condition has a diminished expectation of privacy, and therefore the Supreme Court has held that “[w]hen an officer has reasonable suspicion that a [parolee] ... is engaged in criminal activity, there is enough likelihood that criminal conduct is occurring that an intrusion on the probationer’s significantly diminished privacy interests is reasonable.” Knights, 534 U.S. at 121, 122 S.Ct. 587. However, even assuming that the officers could conduct a constitutionally-acceptable parole search without reasonable suspicion of criminal activity,5 the warrantless search of Mot[1065] ley’s home was unconstitutional for two reasons: first, the officers did not have reasonable grounds to believe that Jamer-son lived or was present at Motley’s residence, and second, the searching officers conducted the search in an unreasonable and harassing manner.
A. Reasonable Grounds to Believe that Jamerson Lived with Motley
To execute an arrest warrant inside a particular residence, law enforcement officers must have reason to believe that the person to be arrested lives at the address to be searched. United States v. Gorman, 314 F.3d 1105, 1111 (9th Cir.2002) (equating “reasonable belief’ standard with “probable cause”). The same standard applies to the determination of whether a parolee is a resident in a specific home, as required before officers can conduct a parole search. See United States v. Harper, 928 F.2d 894, 896 (9th Cir.1991) (requiring probable cause that parolee lived at a certain address before entering the home and executing arrest warrant issued for parole violations); Dally, 606 F.2d at 863 (requiring a reason to believe that parolee lived at a certain residence before conducting parole search). Before Gorman, we had not phrased the applicable standard consistently: some cases stated that officers had to have “probable cause” that a parolee lived at the residence, and other cases stated that the officers needed a “reasonable belief’ that it was the parolee’s residence. The Gorman court held that the two standards required the same, “substantial” evidence of residence. Id. at 1113 (quoting Watts v. County of Sacramento, 256 F.3d 886, 890 (9th Cir.2001), and holding that the probable cause test applied to the execution of an arrest warrant at the suspect’s girlfriend’s house).
Although we did not explicitly equate the “reasonable belief’ standard with probable cause until 2002, it was clear when the officers searched Motley’s home in 1999 that substantial evidence of residence was required. In 1991, we held that the police may only execute an arrest warrant issued by the parole board for a parole violation inside a home “if the [officers] have probable cause to believe the person named in the warrant resides there.” Harper, 928 F.2d at 896.6 Harper cited with approval the 1979 holding in Dally, 606 F.2d at 863, that police were entitled to search a home because there was sufficient evidence to support a reasonable belief that the parolee lived there. Id.; see also Payton v. New York, 445 U.S. 573, 603, 100 S.Ct. 1371, 63 L.Ed.2d 639 (1980) (articulating reasonable belief standard: “an arrest warrant founded on probable cause implicitly carries with it the limited authority to enter a dwelling in [1066] which the suspect lives when there is reason to believe the suspect is within”).
The difference between the “reasonable belief’ language in Dally and the “probable cause” language in Harper caused confusion in our Circuit, because some judges interpreted “reasonable belief’ to be equivalent to “reasonable suspicion.” See United States v. Conway, 122 F.3d 841, 844 (9th Cir.1997) (Wallace, J., concurring) (noting apparent conflict between “reasonable basis” standard in Dally and “probable cause” standard in the more recent Harper case); United States v. Watts, 67 F.3d 790, 795 (9th Cir.1995) (same), overruled on other grounds, 519 U.S. 148, 117 S.Ct. 633, 136 L.Ed.2d 554 (1997). However, despite the confusion about how to interpret “reason to believe,” the cases decided before 1999 which discussed the reasonable belief standard clearly required evidence more substantial than a reasonable suspicion that the suspect or parolee lived at a given residence. See, e.g., Watts, 256 F.3d at 890 (collecting cases and concluding that courts “have generally required substantial evidence pointing to the suspect’s co-resident status to create a reasonable belief that he lives in the home of a third party”); Gorman, 314 F.3d at 1113-14. In addition, Harper was never overruled, which arguably put reasonable officers in 1999 on notice that they were required to have probable cause that a parolee lived at a certain address before searching it.
Regardless of how the standard was expressed, we have found no Ninth Circuit case in which the Court equated “reason to believe” with “reasonable suspicion” and held that a parole search was constitutional where officers had only a reasonable suspicion that the parolee lived at the address. For example, in Dally, which the dissent implies is the only Ninth Circuit case on point, the officers had the following evidence that the parolee, Holiday, lived at the residence they later searched: (1) a federal agent who was also investigating Holiday informed the parole officer that Holiday was living at the address; (2) during a stake-out, officers photographed Holiday taking out the trash, bringing in his laundry, and chatting with the neighbors; (3) a week later, officers returned to find Holiday’s car parked near the house with fogged windows, indicating it had been parked overnight; (4) the next day, Holiday left the house in the morning and got in a car that had been parked overnight; (5) Holiday returned with dry cleaning, changed his clothes, and left the house again, carrying laundry; and (6) Holiday later returned with more dry cleaning, and officers observed him use a key to open the door. Dally, 606 F.2d at 862. For these reasons, it was clearly established in 1999 that before conducting a parole search, officers had to have substantial evidence that a parolee lived at the residence to be searched.
The question, then, is whether based on substantial, trustworthy evidence, a reasonable officer would have believed that Jamerson resided at Motley’s apartment. The officers involved had different knowledge and levels of responsibility: Ruegg supervised the search team; Kading, Sanchez, and Black conducted the search, and Webster was an agent in training who remained behind the house during the search.
1. Supervisor Ruegg
Ruegg was responsible for compiling information on the parolees to be searched. He had been collecting information on parolees since November 1998-over four months before the search of Motley’s home — the time when the Newton Street Station started a new “Career Criminal Unit.” The only function of the Career Criminal Unit was to conduct pa[1067] role searches of Newton Street residents. Although Ruegg testified that he did not himself compile the address information of parolees, he had reason to know that the parolee information was stale.
Further, Ruegg organized and supervised the search team. A supervisor can be liable under section 1983 if he “set[s] in motion a series of acts by others ..., which he knew or reasonably should have known, would cause others to inflict the constitutional injury.” Graves v. City of Coeur D’Alene, 339 F.3d 828, 848 (9th Cir.2003) (citing Larez v. City of Los Angeles, 946 F.2d 630, 646 (9th Cir.1991), and holding that the liability of the superior officer was an issue for the jury). “Supervisory liability may be found in civil rights actions even if the supervisors in question are not directly involved in the acts leading to the constitutional deprivation. Because' there is no dispute that the officers were directly responsible for supervising the search, a jury could properly hold them liable.” Mena, 332 F.3d at 1270 n. 19 (citing Redman v. County of San Diego, 942 F.2d 1435, 1446 (9th Cir.1991) (en banc)). Of particular importance here, officers supervising a search are responsible for making sure that the search is supported by the proper cause. “The officers who lead the team that executes a warrant are responsible for ensuring that they have lawful authority for their actions.... The leaders of [a search] expedition may not simply assume that the warrant authorizes the search and seizure.” Ramirez v. Butte-Silver Bow County, 298 F.3d 1022, 1027 (9th Cir.2002), aff'd by Groh, 540 U.S. 551, 124 S.Ct. 1284, 157 L.Ed.2d 1068 (2004).
Just as a warrant must be supported by probable cause, in March 1999 it was clearly established that officers must have reason to believe that a parolee lives at a certain address; without the requisite cause, the officers cannot constitutionally conduct a parole search. As the supervisor in charge of the search, Ruegg was responsible for ensuring that the searching officers had that substantial evidence. Instead, Ruegg delegated the task of checking Jamerson’s parole status to some unnamed person at least six weeks before the search took place. Ruegg then relied on the stale information, without using any of three easily available methods of checking Jamerson’s parole status on or anytime near the day of the search.7 Ruegg admitted he knew that parolees did not always live at the addresses they listed when they were first released, [ER 166] yet he did not even contact Jamerson’s parole officer to obtain any current information about where Jamerson actually lived. In short, Ruegg dispatched officers to conduct a parole search without any evidence that Jamerson was connected to a specific criminal activity and without sufficient evidence to support probable cause, let alone a reasonable suspicion that Jamerson lived at the given address at the time of the search.
Under these circumstances, as the supervisor of the Unit and the search in question, it was not reasonable for Ruegg to simply assume that the information about Jamerson was accurate. See Ramirez, 298 F.3d at 1027. We therefore reverse the district court’s determination that Ruegg was entitled to qualified immunity for his role in the search.
[1068]*10682. Searching Officers: Kading, Sanchez, and Black
At the time of the search, the officers who conducted the search had the following information about Jamerson’s residence and parole status: at the LAPD briefing, they were informed that Jamerson was on parole and that his last known address was 416 East 40th Place. However, when they arrived at Motley’s residence, she told them that Jamerson did not live there and that he was incarcerated. Other than Kading,8 none of the officers had any independent information that Jamerson lived at the address to be searched. Nor did any of them attempt to confirm the information they were given, even after one of the searching officers lied to Motley, saying Jamerson had been released, and even after Motley emphatically repeated that she knew Jamerson was in custody.
“It is incumbent on the officers] executing a search warrant to ensure the search is lawfully authorized and lawfully conducted.” Groh, 124 S.Ct. at 1293. The Groh Court emphasized that unless there are exigent circumstances, officers are required to carefully ensure that constitutional requirements are met when searching a person’s residence, and are not entitled to qualified immunity when they do not. Id. at 1294 n. 9. The same care, if not more, must be taken when the officers are searching without a warrant, under an exception to the warrant requirement.
The searching officers’ responsibilities include a duty to conduct a reasonable investigation: “Although a police officer is entitled to rely on information obtained from fellow law enforcement officers, ... this in no way negates a police officer’s duty to reasonably inquire or investigate these reported facts.” Mendocino Envtl. Ctr. v. Mendocino County, 192 F.3d 1283, 1293 n. 16 (9th Cir.1999) (citation omitted); cf. United States v. Kyllo, 37 F.3d 526, 529 (9th Cir.1994) (“Furthermore, the fact that [the officer] relied on information received from another law enforcement officer does not ipso facto mean that [he was] not reckless.”); Fuller v. M.G. Jewelry, 950 F.2d 1437, 1444 (9th Cir.1991) (noting that in some circumstances, officers have a duty to investigate further when they obtain additional information at the scene of a crime); Merriman v. Walton, 856 F.2d 1333, 1335 (9th Cir.1988) (holding that even though an initial report that a suspect had committed a kidnapping might have established probable cause, the officer received exculpatory information before arresting the suspect, and a reasonable officer would have investigated further before making the arrest).
Here, the searching officers did not know whether the parolees’ addresses were current; in fact, it appears that they had no information about the searches except the names and last known addresses of the parolees. Several of the officers testified that the purpose of the parole “searches” was to determine if they had current addresses for the parolees, not to force entry and search the homes, because they did not have even reasonable suspicion that the parolees were involved in criminal activity. Given this purpose, and knowing the residence information they [1069] had was not necessarily current, a reasonable officer would have called to check Jamerson’s parole status once Motley stated with certainty that Jamerson was in jail.
Instead, the searching officers lied to Motley about Jamerson’s parole officer being present, their possession of a search warrant, and Jamerson’s custody status. In Harper, we held that the following facts about a parolee’s residence “barely ” constituted probable cause: the parolee’s family leased the house and two of his brothers lived there; the parolee had lived with his family before his incarceration; a source told the officers the parolee lived there; the police conducted repeated surveillance and saw the parolee enter the house with his own key once or twice; and several of the parolee’s known associates had their cars parked outside the home. Harper, 928 F.2d at 896-97. Here, the searching officers had an outdated address and a resident who twice asserted that the parolee was in custody and did not live there. We recognize that law enforcement officers cannot always believe what citizens tell them. However, here, there were no exigent circumstances, the officers had no reasonable suspicion that Jamerson was involved in criminal activity, and Motley told them unequivocally that Jamerson was in custody, even in the face of the officers’ lies. The officers had only been given Jamerson’s name and last known address and they knew the information might not be current because of the transient nature of parolees. Once Motley informed them that Jamerson did not live there, all the officers would have had to do is make one phone call to determine whether Jamerson was in custody. They did not. If Motley’s testimony is true, it was not reasonable for the searching officers to believe that Jamerson lived in Motley’s home.
3. Agent Webster
Webster was an officer in training and did not participate in the search of Motley’s home. He was behind the house with Black when the other officers approached the door, and remained behind the house even when Motley came to the door and Black went to the front. Webster’s actions were reasonable under the circumstances, and we affirm the district court’s grant of summary judgment in his favor.
B. Parole Search Conducted in a Harassing Manner
Even if the officers had substantial reason to believe that Jamerson lived in Motley’s home, Kading, Sanchez, and Black would be liable for violating Motley’s Fourth Amendment rights, because they conducted — or allowed the search to be conducted — in an unconstitutional manner. It has long been clear that a parole search is unreasonable under the Fourth Amendment if it is conducted in a harassing manner. See United States v. Consuelo-Gonzalez, 521 F.2d 259, 265 (9th Cir.1975) (en banc) (holding that a “probationer, like the parolee, has the right to enjoy a significant degree of privacy,” which is infringed when a parole search is “intimidating and harassing”); Latta v. Fitzharris, 521 F.2d 246, 252 (9th Cir.1975) (en banc) (“In a given case, what is done may be so unreasonable as to require that the search be held to violate the Fourth Amendment. For example, harassment or intimidation is no part of a parole officer’s job.”); see also People v. Reyes, 19 Cal.4th 743, 80 Cal.Rptr.2d 734, 968 P.2d 445, 450 (Cal.1998) (noting that a parole search is not reasonable under the Fourth Amendment if it is “arbitrary, capricious or harassing”); People v. Bravo, 43 Cal.3d 600, 238 Cal.Rptr. 282, 738 P.2d 336, 340 (1987) (“[O]fficers cannot act arbi[1070] trarily or capriciously or harass a probationer. ..
In some parole search cases before 2001, courts held that a parole search was unreasonable under the Fourth Amendment because it was conducted for an improper or harassing purpose that did not serve the interests of parole or probation supervision. See, e.g., United States v. Johnson, 722 F.2d 525, 527-28 (9th Cir.1983). However, in 2001, the Supreme Court abrogated Johnson and other cases containing similar reasoning, stating that “[w]ith the limited exception of some special needs and administrative search cases, ‘we have been unwilling to entertain Fourth Amendment challenges based on the actual motivations of individual officers.’ ” Knights, 534 U.S. at 122, 122 S.Ct. 587 (quoting Whren v. United States, 517 U.S. 806, 813, 116 S.Ct. 1769, 135 L.Ed.2d 89 (1996)) (internal citations omitted). Because the prohibition in Knights only prevents courts from relying on searching officers’ subjective intent to harass when assessing the reasonableness of a search under the Fourth Amendment, it is clear that courts must still hold that a parole search is unreasonable if conducted in a harassing manner.9 This was clearly established in 1999, and is still the law today.10
The officers who searched Motley’s residence for purported parolee Janae Jamer-son conducted the search in a harassing manner. When Motley came to the door in her pajamas, the officers told her several falsehoods. Fading said that he was there with Jamerson’s parole officer and that they had a warrant to search the apartment, neither of which was true. Motley told the searching officers that Jamerson did not live there and was in custody. One of the officers then told her that Jamerson had been released three days earlier, another lie. When the officers then asked Motley who else was inside the house with her, she said that only she and her five-week-old son were there. Fading told Motley that if she did not let them in, they would arrest her and put her son in foster care. Faced with Fading’s threat to take her son away, Motley unlocked the security gate. Fading pushed her out of the way and against the wall with his forearm as he went into the house. The officers all entered the apartment with their guns drawn. During the search, the officers were “going through things,” including closets and a file box, a search that was completely unauthorized.
Fading knew that the baby was in the back bedroom, and as soon as he entered that room he pointed his gun directly at the five-week-old infant. The baby was on his back on the bed looking toward the bedroom door. The baby began screaming as soon as Fading entered, and so Motley ran to the room, where Fading was still pointing the gun at the baby. Fading did [1071] not move his gun when Motley entered, and he kept it pointed at Motley’s tiny son while he searched the room.
The officers searched for over twenty minutes when it could have been ascertained much more quickly that Jamerson was not present.
During the course of the search, they questioned Motley about her baby’s father and laughed at her when she revealed that it was Jamerson. The officers appeared to ogle the belongings in the two-bedroom apartment: Kading inquired about the whereabouts of “that really nice ping pong table.” Even though the officers found neither Jamerson nor contraband, for which they had no authority to search, one of them felt it necessary to issue a parting threat: “Tell them that Newton Street was here.” The searching officers showed no respect for Motley, her baby, her home, or her privacy. They lied to her, shoved her, made fun of her, and pointed a gun at her five-week-old baby.
Of the four officers who went to Motley’s apartment, only Webster never entered the home. Each of the other officers either participated in harassing and intimidating Motley and her child during the search, or failed to intervene to stop the harassment. See United States v. Koon, 34 F.3d 1416, 1447 n. 25 (9th Cir.1994) (“[A]n officer who failed to intercede when his colleagues were depriving a victim of his Fourth Amendment right to be free from unreasonable force in the course of an arrest would, like his colleagues, be responsible for subjecting the victim to a deprivation of his Fourth Amendment rights.”); Robins v. Meecham, 60 F.3d 1436, 1442 (9th Cir.1995) (holding that “a prison official can violate a prisoner’s Eighth Amendment rights by failing to intervene” when another official acts unconstitutionally); O’Neill v. Krzeminski, 839 F.2d 9, 11 (2d Cir.1988) (“A law enforcement officer has an affirmative duty to intercede on the behalf of a citizen whose constitutional rights are being violated in his presence by other officers.”). If Motley’s testimony is true, any reasonable officer would have known that this search was harassing and unreasonable under the Fourth Amendment. See Saucier, 533 U.S. at 202, 121 S.Ct. 2151 (holding that officers not entitled to qualified immunity if “it would be clear to a reasonable officer that his conduct was unlawful in the situation he confronted”). Kading, Black, and Sanchez are not entitled to qualified immunity for the unconstitutional search of Motley’s home.
III. Qualified Immunity for Use of Excessive Force
Additionally, we reverse the district court’s grant of qualified immunity to Kading on the excessive force claim. Use of a weapon against someone who is helpless constitutes excessive force. Headwaters Forest Defense v. County of Humboldt, 276 F.3d 1125, 1130 (9th Cir.2002). Pointing a gun at a person’s head can constitute excessive force. See Robinson v. Solano County, 278 F.3d 1007, 1014-15 (9th Cir.2002) (en banc) (handcuffing and pointing a gun at misdemeanor suspect was excessive force where he posed no threat to officers and crime was not serious). Most importantly, in 1999, no reasonable officer could have believed that pointing a gun at a child, particularly a five-week-old baby, was reasonable during the course of a non-exigent (and unconstitutional) search. See McDonald by McDonald v. Haskins, 966 F.2d 292, 294 (7th Cir.1992) (holding a gun to the head of a child during search of the child’s residence constituted excessive force and officer was not entitled to qualified immunity despite the fact that no previous case law specifically established the unreasonableness of such an egregious act). Officer Kading is [1072] not entitled to qualified immunity for pointing a deadly weapon at a tiny infant.
IV. Monell Claims
We agree with the district court that Motley has not presented evidence sufficient to establish Monell liability for her excessive force and unconstitutional search claims. We therefore affirm the dismissal of her claims against former LAPD police chiefs Parks and Gates.
CONCLUSION
We reverse the district court’s decision that Kading, Black, Sanchez, and Ruegg are entitled to qualified immunity. We affirm the district court’s grant of summary judgment to Parks, Gates, and Webster. We also affirm the district court’s decision on the Monell claims. Appellants are entitled to costs.
REVERSED IN PART; AFFIRMED IN PART.