In order to violate Penal Code section 290, a defendant must have actual knowledge of the sexual offender registration requirement. Therefore, where appellant’s defense was that he had never been advised of a registration requirement, it was error for the trial court to have failed to make it clear to the jury that a “willful” failure to register required a finding that appellant knew about his duty to register. It was also error for the court to have instructed that the “ignorance of the law is no excuse” which allowed the jury to convict even if appellant was unaware of the registration requirement. However, the error was harmless beyond a reasonable doubt because there was strong evidence that appellant had actual knowledge of the registration requirement. J. Kennard dissented, finding that the trial court’s failure to instruct on the element of actual knowledge was not harmless error. Reversal was not required where appellant was not given a copy of the signed form which required him to register as a sex offender. Technical omissions of this kind are not grounds for reversal. J. Kennard dissented, finding that the trial court’s failure to instruct on the element of actual knowledge was not harmless error.