Yet again (or still), no one is asking how the registry is such a great law enforcement tool. Everything the registry has is on NCIC and state counterparts. The registry has never prevented one single crime from being committed or was instrumental solving one single case. Google or Bing the term “sex offender arrested” and virtually all hits will regard parole or probation violations or status/registry created offenses. In the one or two that do not, the registry status of the accused is never known until after arrest, illustrating the registry is useless, LE only or not.
What is on the registry that is not immediately available from other sources? Nothing. Names, addresses, photos, and crimes of conviction are all in NCIC. The LE version may include fingerprints and maybe a DNA sample but again, already in NCIC. NCIC also lists all non-sex related arrests and convictions; the registry does not.
These are not arbitrary musings. Most cops will privately tell you the registry is useless for those very reasons. Those that don’t are the ones that get a thrill out of harassing registrants and I, for one doubt that that is coincidence.