Primarily, states are using it to monitor people on probation, parole or registered sex offenders. It is also used for school teachers, daycare center employees, and anyone deemed to be in positions of trust which require notification of arrests or encounters with LE.
If a registered sex offender (or school teacher) gets arrested in NV with an underage prostitute, the system would let HPD, employers (Dept of Ed) and any other subscribers know of the arrest. Otherwise, it may never be reported locally.