28 CFR §811.3

1. (a)Sex offenders may be notified of their obligation to register under various provisions of law. See sections 4, 6 and 8 of the Sex Offender Registration Act of 1999 (D.C. Official Code sections 22-4003, 4005, 4007) (relating to notice by the District of Columbia Superior Court, Department of Corrections, or CSOSA); 18 U.S.C. 4042(c) (relating to notice by Federal Bureau of Prisons and probation offices); 18 U.S.C. 3563(a)(8), 3583(d), 4209(a) (inclusion of registration requirements as conditions of release under federal law); 42 U.S.C. 14071(b)(1) (notice under federal law standards for state sex offender registration programs).
2. (b)In some cases, sex offenders may not be notified of their obligation to register. Lack of notice does not excuse a failure to register because sex offenders have an independent obligation to register. Persons who have been convicted or found not guilty by reason of insanity of a sex offense or who have been determined to be a sexual psychopath should report to CSOSA in order to ascertain whether they are required to register.