Federal law punishes convicted sex offenders for failure to register as the Sex Offender Registration and Notification Act (SORNA) demands. The offense consists of three elements: (1) a continuing obligation to report to the authorities in any jurisdiction in which the individual resides, works, or attends school; (2) the knowing failure to comply with registration requirements; and (3) a jurisdictional element, i.e ., (a) an obligation to register as a consequence of a prior qualifying federal conviction or (b)(i) travel in interstate or foreign commerce, (ii) travel into or out of Indian country; or (iii) residence in Indian country. Violators face imprisonment for not more than 10 years. If an offender also commits a federal crime of violence, the registration transgression carries an additional penalty of imprisonment for not more than 30 years, but not less than 5 years. The Adam Walsh Child Protection and Safety Act created SORNA. SORNA called for a revision of an earlier nationwide sex offender registration system. Its predecessor, the Jacob Wetterling Act, encouraged the states to establish and maintain a registration system. Each of them had done so. Their efforts, however, though often consistent, were hardly uniform. The Walsh Act preserved the basic structure of the Wetterling Act, expanded upon it, and made more specific matters that were previously left to individual state choice. The Walsh Act contemplated a nationwide, state-based, publicly available, contemporaneously accurate, online system. Jurisdictions that failed to meet the Walsh Act's threshold requirements faced the loss of a portion of their federal criminal justice assistance grants. The Walsh Act vested the Attorney General with authority to determine the extent to which SORNA would apply to those with qualifying convictions committed prior to enactment. He promulgated implementing regulations imposing the registration requirements on those with pre-enactment convictions. Conscious of the legal and technical adjustments required of the states, the Walsh Act afforded jurisdictions an extension to make the initial modifications necessary to bring their systems into compliance. Thereafter, states not yet in compliance have been allowed to use the penalty portion of their federal justice assistance funds for that purpose. The Justice Department indicates that 17 states, 3 territories, and numerous tribes are now in substantial compliance with the 2006 legislation. Section 2250 convictions require the government to prove that (1) the defendant had an obligation under SORNA to register and to maintain the currency of his registration information; (2) that the defendant knowingly failed to comply; and (3) that one of the section's jurisdictional prerequisites has been satisfied. Obligation to Register and Maintain Registration : SORNA directs anyone previously convicted of a federal, state, local, tribal, or foreign qualifying offense to register and to keep his registration information current in each jurisdiction in which he resides, or is an employee or student. Initially, he must also register in the jurisdiction in which he was convicted if it is not his residence. Registrants who relocate or who change their names, jobs, or schools have three days to appear and update their registration in at least one of the jurisdictions in which they reside, work, or attend school. SORNA defines broadly the terms "student," "employee," and "resides." For example, "[t]he term 'resides' means, with respect to an individual, the location of the individual's home or other place where the individual habitually lives." SORNA's use of the phrase "resides ... in a [U.S.] jurisdiction," led the Supreme Court to conclude recently in Nichols v. United States that the maintenance requirement of Section 16913(c) does not apply to offenders who relocated abroad, i.e ., outside of any U.S. "jurisdiction." Anticipating the limit identified in Nichols , Congress passed the International Megan's Law to Prevent Child Exploitation and Other Sexual Crimes Through Advanced Notification of Traveling Sex Offenders [Act], which among other things, amends SORNA to compel offenders to supplement their registration statements with information relating to their plans to travel abroad. Qualifying Convictions : Only those who have been convicted of a qualifying sex offense need register. There are five classes of qualifying offenses: (1) designated federal sex offenses; (2) specified military offenses; (3) crimes identified as one of the "special offenses against a minor"; (4) crimes in which some sexual act or sexual conduct is an element; and (5) attempts or conspiracies to commit any offense in one of these other classes of qualifying offenses. (A more specific list is attached). Certain foreign convictions, juvenile adjudications, and offenses involving consensual sexual conduct do not qualify as convictions that require the offender to register under SORNA. Knowing failure to register : Section 2250's second element is a knowing failure to register or to maintain current registration information as required by SORNA. The government must show that the defendant knew of his obligation and failed to honor it; the prosecution need not show that he knew he was bound to do so by federal law generally or by SORNA specifically. Jurisdictional elements : Section 2250 permits conviction on the basis of any three jurisdictional elements: a prior conviction of one of the federal qualifying offenses; residence in, or travel to or from, Indian country; or travel in interstate or foreign commerce. Federal crimes : Interstate travel is not required for a conviction under §2250. An individual need only have a knowing failure to register and a prior conviction for a qualifying sex offense under federal law or the law of the District of Columbia, the Code of Military Justice, tribal law, or the law of a United States territory or possession. Federal jurisdiction flows from the jurisdictional basis for the underlying qualifying offense. Indian country : Travel to or from Indian country, or living there, will also satisfy Section 2250's jurisdictional requirement. "Indian country" consists primarily of Indian reservations, lands over which the United States enjoys state-like exclusive or concurrent legislative jurisdiction. Interstate travel : Interstate travel is the most commonly invoked of Section 2250's jurisdictional elements. It applies simply to anyone who travels in interstate or foreign commerce with a prior federal or state qualifying offense who fails to register or maintain his registration. In the case of foreign travel it also applies to anyone who fails to supplement his registration with information concerning his intent to travel abroad. The qualifying offense may predate SORNA's enactment; the travel may not. Venue and Bail : Although the question may not be beyond dispute, a Section 2250 prosecution involving interstate travel may be brought either in the state of origin or the state of destination. Federal bail laws permit the prosecution to request a pre-trial detention hearing prior to the pre-trial release of anyone charged with a violation of Section 2250. The individual may only be released prior to trial under condition, among others, that he be electronically monitored; be subject to restrictions on his personal associations, residence, or travel; report regularly to authorities; and be subject to a curfew. Imprisonment : Upon conviction, the individual may be sentenced to imprisonment for a term of not more than 10 years and/or fined not more than $250,000. Section 2250 also sets an additional penalty of not more than 30 years, but not less than 5 years, in prison for the commission of a federal crime of violence when the offender has also violated Section 2250. Supervised release : As a general rule, when a court sentences a defendant to prison, it may also sentence him to a term of supervised release. Supervised release is a parole-like regime under which a defendant is subject to the oversight of a probation officer following his release from prison. In the case of a conviction under Section 2250, the court must order the defendant to serve a life-time term of supervised release or in the alternative a term of 5 years or more. The statute and the Sentencing Guidelines establish an array of mandatory and discretionary conditions for those on supervised release. The mandatory conditions require the defendant to: (1) avoid committing any additional federal, state or local offenses; (2) refrain from the unlawful possession of controlled substances; (3) participate in a domestic violence rehabilitation program, he has been convicted of domestic violence; (4) submit to periodic drug tests, unless the court suspends the condition because the defendant poses a low risk of future substance abuse; (5) pay installments to satisfy any outstanding fines or special assessments; (6) satisfy any outstanding restitution requirements; (7) comply with any SORNA registration demands; and (8) submit to the collection of a DNA sample. A sentencing court may also impose any condition from the statutory inventory of discretionary conditions for probation. In addition, t he Sentencing Guidelines specify thirteen "standard" conditions; eight "special" conditions; and "additional" special conditions. Finally, the district court may impose any "specific" condition that is no greater impairment of liberty than necessary and that is reasonably related to the nature of the offense, the offender's criminal history, and various general statutory sentencing factors. The court may modify the conditions of supervised release at any time. It may also revoke the defendant's supervised release and sentence him to prison for violations of the conditions of supervised release. Much of the litigation relating to Section 2250 relates to constitutional challenges involving either Section 2250 or SORNA. The attacks have taken one of two forms. One argues that SORNA or Section 2250 operates in a manner which the Constitution specifically forbids, for example in its clauses on Ex Post Facto laws, Due Process, and Cruel and Unusual Punishment. The other argues that the Constitution does not grant Congress the legislative authority to enact either Section 2250 or SORNA. These challenges probe the boundaries of the Commerce Clause, the Necessary and Proper Clause, and the Spending Clause, among others.