In 1998, T.R.D. (defendant) was convicted of sexual assault and risk of injury to a child, and was sentenced to 12 years in prison with probation available after five years. Prior to T.R.D.’s release to probation in November 2002, a correction officer met with T.R.D. to explain that T.R.D. must register with Connecticut’s sex-offender registry. The registry required T.R.D. to report in person at specified intervals and routinely return address-verification letters mailed to the registrant’s address of record every 90 days. If a registrant did not respond to an address-verification letter, two more were sent within the same 90-day period. T.R.D. signed two documents attesting to his understanding of these requirements and the potential criminal consequences for noncompliance. In February 2003, T.R.D. failed to return the first letter, but responded to the second letter and verified that his address remained the same. In May 2003, during the second 90-day interval after T.R.D.’s release, T.R.D. failed to respond to any of the three letters, and his status was considered unknown. In February 2004, T.R.D. was arrested. A jury found T.R.D. guilty of violating General Statutes § 54-251 and § 54-257, which criminalize failure to register as a sex offender and failure to comply with the address-verification requirements of the registry. T.R.D. appealed on the ground that the trial court erred by not instructing the jury as to a mens rea requirement for the offenses.