[120]*120OPINION
By the Court,
Shearing, J.:
Police investigators observed appellant Arthur J. Graves, within hours after his release from the Clark County Detention Center, entering casinos, suspiciously walking up and down the aisles, observing and spying on casino patrons, and exiting. He allegedly attempted to steal from a patron at the Fremont Casino and a casino cage at the Horseshoe Casino. The next evening, after police investigators observed Graves and two individuals enter a casino, walk around observing patrons, and approach the patrons, but observing no criminal act, the police, without a warrant, arrested Graves.
On the first day of trial, Graves moved the court to allow him to represent himself. After canvassing Graves, the district court granted Graves’ request, but postponed the trial for three weeks to allow him to prepare for trial. Graves objected, arguing that [121]*121the postponement would deny him the right to trial within sixty days. The district court overruled Graves’ objection. Graves was convicted at trial, pursuant to a jury verdict, on two counts of burglary.
On appeal, Graves claims that he did not knowingly and intelligently waive his right to counsel. He also asserts other errors: lack of substantial evidence to support the jury’s verdict, improper joinder of charges, denial of his right to a speedy trial, and the warrantless arrest.
On the first day of trial, Graves’ appointed attorney informed the district court that Graves wished to bring a motion before the court to be appointed as his own counsel. The following canvass ensued:
THE COURT: You desire to represent yourself still, Mr. Graves?
THE DEFENDANT: Yes.
THE COURT: I’m going to give you a canvas [sic], which we need to do to see if you’re able to do that.
First off, let me say it amazes me you would want to do this. You have one of the best, if not the best criminal attorney [sic] in this town and you want to set him aside and represent yourself?
THE DEFENDANT: If it’s okay with the Court I’d like to do that.
THE COURT: It’s your choice to make. I just want you to know some of the things involved in making that choice.
You do know you have a constitutional right under the Faretta ruling to represent yourself if you wish to; do you?
THE DEFENDANT: Yes.
THE COURT: Have you talked this over with your attorney?
THE DEFENDANT: Yes, I have.
THE COURT: And you wish to represent yourself?
THE DEFENDANT: Yes, I do.
THE COURT: Do you think it would be in your best interest to do so?
THE DEFENDANT: Yes, I do.
THE COURT: I have to tell you that if you do represent yourself, that you’ll be held to every standard as far as procedure and all the rules of the Court that you would have if you had the assistance of an attorney; do you understand that?
THE DEFENDANT: Why [sic], Your Honor.
THE COURT: You also understand you’ll be giving up some rights, some constitutional rights which you might [122]*122have had if you had had an attorney when you act as your own attorney; do you understand that?
THE DEFENDANT: Right, Your Honor.
THE COURT: One of those rights is if you act as your own counsel you cannot then at a later time have an appeala-ble issue on ineffective assistance of counsel because you’ll be doing that yourself.
THE DEFENDANT: Right.
THE COURT: Do you understand that?
THE DEFENDANT: Yes, Your Honor.
THE COURT: So even if you are ineffective, no matter how ineffective you are, you lose that right at any later time on appeal to say that you had ineffective assistance of counsel; do you understand that?
THE DEFENDANT: Yes, Your Honor.
THE COURT: Have you had an opportunity to look at all the discovery that Mr. Amundson has provided you?
THE DEFENDANT: Yes, Your Honor, I’ve had preliminary transcript for over a month, I have the police reports. I’m ready, Your Honor. I’ve reviewed them several times.
THE COURT: I want you to know that I, especially in this case, since you have a good attorney representing you, that I think it’s a mistake for you to represent yourself; do you understand that?
THE DEFENDANT: Yes.
THE COURT: I also have to inform you that you will have no license to abuse the dignity of the Court if you represent yourself; that is, I’ll hold you to the same standard of decorum and same — and all the same rules if you represent yourself. And if it comes to the point you do disrupt the Court when you represent yourself, do you understand that I will then terminate your representation and assign an attorney to finish out the trial? Do you understand that?
THE DEFENDANT: Yes, Your Honor.
THE COURT: In other words, you just have to be as nice as an attorney would be in representing yourself.
THE DEFENDANT: I understand.
THE COURT: Sometimes that isn’t too nice but you’ll at least be held to that same standard; do you understand that?
THE DEFENDANT: Yes, Your Honor.
THE COURT: Do you also understand that at the time of trial, if you represent yourself, I’m going to appoint Mr. Amundson to be your stand-by counsel; do you understand that?
[123]*123THE DEFENDANT: Yes, Your Honor.
THE COURT: And he’ll be sitting there and you can ask him anything you wish to ask him about procedure, but I’ll not allow him to react to the procedure in any other way. That is, I won’t be allowing your stand-by counsel to make any objections or anything else during the course of a trial. When an objection is missed at trial it will be because you missed it and that’s one of the penalties of representing yourself?
THE DEFENDANT: Yes.
THE COURT: But I will allow you at the time of trial, I’ll give you time to talk to Mr. Amundson and inquire of him of any advice that you may need at the time of trial; do you understand that?
THE DEFENDANT: Yes, sir.
THE COURT: In the dissenting opinion of Feretta [sic], after they say that it’s a constitutional right of a defendant to be able to represent himself, they also say that gives the defendant a constitutional right to make a fool of himself because of the old proverb which says one who represents himself has a fool for a client.
THE DEFENDANT: Yes, Your Honor.
THE COURT: Do you understand that?
THE DEFENDANT: Yes, Your Honor.
THE COURT: And I want you to know that I feel that’s true; do you know that?
THE DEFENDANT: I do.
THE COURT: I have to tell you, after I’ve seen many defendants represent themselves that I think that’s more true than ever, that it’s a foolish thing to do; do you understand that?
THE DEFENDANT: Yes.
THE COURT: Do you still want to do it?
THE DEFENDANT: Yes, I do, Your Honor.
THE COURT: All right. I’ll allow you to represent yourself.
Graves argues that the district court’s canvass was insufficient and requires reversal of his conviction because the district court never explained the facts, the nature of the charges or offenses, or potential defenses the defendant faced or could use. Graves further notes that the district court never explained the allowable punishments or the possibility of being sentenced under the habitual criminal statute. Finally, Graves notes that he had not represented himself previously and that the district court made no specific inquiry into his background and experience. Thus, he [124]*124claims that he could not have knowingly and intelligently waived his rights.
The United States Supreme Court stated in Faretta v. California, 422 U.S. 806 (1975):
Although a defendant need not himself have the skill and experience of a lawyer in order competently and intelligently to choose self-representation, he should be made aware of the dangers and disadvantages of self-representation, so that the record will establish that “he knows what he is doing and his choice is made with eyes open.” Adams v. United States ex rel. McCann, 317 U.S. at 279.
. . . We need make no assessment of how well or poorly Faretta had mastered the intricacies of the hearsay rule and the California code provisions that govern challenges of potential jurors on voir dire. For his technical legal knowledge, as such, was not relevant to an assessment of his knowing exercise of the right to defend himself.
Id. at 835-36 (footnote omitted).
We believe that the record clearly demonstrates that Graves was aware of the dangers and disadvantages of self-representation. The judge repeatedly warned Graves of the dangers and disadvantages and explicitly outlined many of them. As already noted in the Faretta quotation, no assessment need be made as to how well or poorly a defendant has mastered the intricacies of court procedures and rules. The only question is whether the defendant “competently and intelligently” chose self-representation, not whether he was able to “competently and intelligently” represent himself.
Faretta makes clear that the defendant’s technical knowledge is not the relevant inquiry. 422 U.S. at 835-36. In order for a defendant’s waiver of the right to counsel to withstand constitutional scrutiny, the judge need only be convinced that the defendant made his decision with a clear comprehension of the attendant risks. Trial judges must determine whether defendants waive their right to counsel with a Ml understanding of the disadvantages. This court will give deference to their decisions. Through face-to-face interaction in the courtroom, the trial judges are much more competent to judge a defendant’s understanding than this court. The cold record is a poor substitute for demeanor observation.
The fact that the canvass did not expressly cover Graves’ [125]*125background, education or experience did not mean that the judge could not learn a great deal about his level of intelligence and ability from his dialogue with the defendant. In any event, the judge had the record before him from which he could see that the defendant had previous experience in preliminary hearings and trials. Moreover, Graves affirmatively established that he had reviewed the preliminary hearing transcript and all the police reports which would be necessary for cross-examination of witnesses. In addition, the judge had before him a pro se Motion to Dismiss from which the judge could determine the defendant’s level of legal knowledge regarding his case. This evidence certainly supplied a sufficient basis for the judge to determine that Graves had the minimum intelligence and ability necessary to represent himself.
Graves also faults the trial judge for not determining that he understood the nature of the charges he faced, possible defenses, or the range of the allowable punishments involved. However, Faretta does not require an explanation regarding the elements of the crimes charged and the possible defenses. Arajakis v. State, 108 Nev. 976, 980, 843 P.2d 800, 802-03 (1992).
In Haberstroh v. State, 109 Nev. 22, 26, 846 P.2d 289, 292, cert. denied, 510 U.S. 858, 114 S. Ct. 169 (1993), this court rejected the necessity of a mechanical performance of a Faretta canvass. Even the omission of a canvass is not reversible error if “it appears from the whole record that the defendant knew his rights and insisted upon representing himself.” Wayne v. State, 100 Nev. 582, 585, 691 P.2d 414, 416 (1984) (quoting Cooley v. United States, 501 F.2d 1249, 1252 (9th Cir. 1974), cert. denied, 419 U.S. 1123 (1975)). In Arajakis, this court stated:
“The test of a valid waiver of counsel is not whether specific warnings or advisements were given but whether the record as a whole demonstrates that the defendant understood the disadvantages of self-representation, including the risks and complexities of the particular case.”
108 Nev. at 980, 843 P.2d at 802-03 (quoting People v. Bloom, 774 P.2d 698, 716 (Cal. 1989), cert. denied, 494 U.S. 1039 (1990)). Based on the record as a whole, we believe Graves made a valid waiver. To the extent that any of our prior cases hint that specific matters should be part of a canvass that go beyond the general requirements of Faretta, we note that those specific matters are not constitutionally required for a valid waiver where it is apparent from the record that the defendant was aware of the dangers and disadvantages of self-representation.
[126]*126Defendants like Graves have had several encounters with the court system and many years of experience in jailhouse tutelage in manipulation of the law. They understand that if they represent themselves, there is a good chance that an appeals court will reverse their convictions. It is unfair to the citizens of this state to give these defendants new trials when they insist on representing themselves despite all warnings. Furthermore, Graves had competent counsel standing by throughout his trial for consultation. His judgment of conviction cannot be reversed on the basis of his knowing and intelligent choice to represent himself.
Graves next claims that there was insufficient evidence to convict him of burglary.1 As to the Fremont incident, he asserts that the jury could not have inferred from the evidence that he had the necessary intent to commit larceny when he entered the Fremont Casino. He claims that his walking in and out of casinos proves nothing, as people do this activity every day. Next, he claims that the evidence merely demonstrated that he dropped some coins beside a patron, bent down to pick up the coins, and engaged in conversation with the patron. Indeed, the two police officers observing Graves testified that they did not see Graves commit a crime while in the Fremont. As to the Horseshoe incident, Graves insists that there was no evidence beyond a reasonable doubt that Graves actually took anything from the cashier’s booth. Moreover, he claims that the evidence did not demonstrate, to the required level, that he had the intent to steal when he entered the Horseshoe Casino.
The standard for determining whether a jury verdict is supported by substantial evidence is “‘whether, after viewing the evidence in the light most favorable to the prosecution, any rational trier of fact could have found the essential elements of the crime beyond a reasonable doubt.’ ” Koza v. State, 100 Nev. 245, 250, 681 P.2d 44, 47 (1984) (quoting Jackson v. Virginia, 443 U.S. 307, 319 (1979)).
We conclude that substantial evidence existed to allow a jury to find that Graves committed two counts of burglary beyond a reasonable doubt.2 We note that “[bjecause burglary is com[127]*127monly committed in secret, ... it frequently must be proved by circumstantial evidence.” Edwards v. State, 90 Nev. 255, 258, 524 P.2d 328, 331 (1974).
Graves next claims that the two charges of burglary are substantially different and do not evidence a common scheme or plan and therefore the two burglary charges were improperly joined in the information. The first charge of burglary related to an alleged attempt to steal money from a patron of the Fremont. The second charge related to an alleged effort to steal money from a cashier’s booth. Graves insists that these acts do not represent a common scheme or plan or involve the same act or transaction as is required by NRS 173.115. He claims that the proof presented at trial regarding his intent to steal from the cashier’s booth was highly prejudicial to the charged intent to steal at the Fremont, given the lack of evidence that he actually stole anything at the Fremont.
NRS 173.115 states:
Two or more offenses may be charged in the same indictment or information in a separate count for each offense if the offenses charged, whether felonies or misdemeanors or both, are:
1. Based on the same act or transaction; or
2. Based on two or more acts or transactions connected together or constituting parts of a common scheme or plan.
[128]*128The district court did not abuse its discretion in allowing the two charges to be joined because the two charged offenses were part of a common scheme or plan and factually connected. See State v. Boueri, 99 Nev. 790, 672 P.2d 33 (1983). Graves systematically walked from casino to casino and acted similarly suspicious at each casino. Consequently, the two charged offenses were sufficiently connected to comprise a common scheme or plan.
Because Graves specifically requested that his trial be held within 60 days, he contends that the district court abused its discretion in overruling his objection and postponing the trial three weeks and then later postponing the trial another day.
“In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial. . . U.S. Const, amend. VI. The factors to be considered in assessing a denial of a speedy trial claim are: “the length of the delay, the reason for the delay, the assertion of the right, and prejudice to the accused.” Brinkman v. State, 95 Nev. 220, 222, 592 P.2d 163, 164 (1979) (citing Barker v. Wingo, 407 U.S. 514 (1972)). NRS 178.556(1) provides that a defendant should be brought to trial within 60 days after the arraignment on the indictment or information. Nevertheless, in Rodriguez v. State, 91 Nev. 782, 542 P.2d 1065 (1975), this court concluded that the “failure to set a trial within 60 days is not per se equatable to a denial of a speedy trial.” Id. at 784, 542 P.2d at 1065.
We conclude that the court rationally postponed the trial to allow Graves, who moved to represent himself the first day of trial, more time to prepare his defense. Cf. Brinkman, 95 Nev. at 223, 592 P.2d at 164-65 (161 day delay between time information was filed and trial not prejudicial to defendant when delay mostly occasioned by actions of defendant or his attorney); Hampton v. Sheriff, 86 Nev. 157, 465 P.2d 615 (1970) (any delay in bringing habeas corpus petitioner to trial was a direct result of his conduct and choice of procedural maneuvers). The fifteen-day delay certainly was not oppressive and had no prejudicial effect on Graves. See Brinkman, 95 Nev. at 223, 592 P.2d at 165; Ex Parte Hansen, 79 Nev. 492, 495, 387 P.2d 659, 660 (1963).
Graves next contends that there is no evidence that he was engaged in criminal activity on the day he was arrested. Indeed, the arresting officer admitted that he did not observe Graves commit any wrongdoing on the day of his arrest. Graves argues that it was improper for the police to arrest him without a warrant for alleged criminal actions he had performed twenty-four hours earlier. He notes that the police continued observations of him for several hours before arresting him, and they did not obtain an [129]*129arrest warrant. Because the police had more than sufficient time to obtain an arrest warrant and Graves did not commit any criminal activity the day of his arrest, he argues that his Fourth Amendment rights were violated and that the convictions should be set aside.
We first note that an illegal arrest alone does not entitle a defendant to have a conviction set aside. United States v. Crews, 445 U.S. 463, 474 (1980) (“[T]he illegality of [a defendant’s] detention cannot deprive the Government of the opportunity to prove his guilt through the introduction of evidence wholly untainted by the police misconduct.”). In any event, we conclude that there was probable cause to support Graves’ arrest, and it therefore was legal. Given the surrounding facts of the burglaries, probable cause did not fade away merely because the police arrested Graves the following day. “Law enforcement officers are under no constitutional duty to call a halt to a criminal investigation the moment they have the minimum evidence to establish probable cause, a quantum of evidence which may fall far short of the amount necessary to support a criminal conviction.” Hoffa v. United States, 385 U.S. 293, 310 (1966). Accordingly, we conclude that Graves’ arrest did not violate his constitutional rights.
For the foregoing reasons, we affirm Graves’ judgment of conviction.
Steffen, C. J., and Young, J., concur.