The Ventura County Sheriff's Office says they conducted what are known as compliance checks at the residences of registered sex offenders near Oxnard last Saturday.
Detectives went to the residences of 28 registered sex offenders in the uncorporated areas near Oxnard.
They say that 23 of the 28 were found to be in compliance.
In the remaining five cases, the registrants were either not home or had moved.
Detectives says they will follow up to determine if they are in compliance or not.
If they are not, they could be facing arrest and new charges.