As the DOJ explains, the proposed rule “will facilitate enforcement of SORNA’s registration requirements through prosecution of non-compliant sex offenders under 18 U.S.C. 2250. By providing a comprehensive articulation of SORNA’s registration requirements in regulations addressed to sex offenders, it will provide a more secure basis for prosecution of sex offenders who engage in knowing violations of any of SORNA’s requirements. It will also resolve a number of specific concerns that have arisen in past litigation or could be expected to arise in future litigation, if not clarified and resolved by this rule. For example, as discussed below, the amendment of § 72.3 in the rule will ensure that its application of SORNA’s requirements to sex offenders with pre-SORNA convictions is given effect consistently, resolving an issue resulting from the decision in United States v. DeJarnette, 741 F.3d 971 (9th Cir. 2013).”

In plain English, the DOJ wants to make it easier to prosecute people (for example, the homeless) who fail to comply with their federal registration obligations.