Investigators from multiple agencies including the Santa Clara County Sheriffs Department, the U.S. Marshals Service and the FBI are working together to find sex offenders who registered as transients.
Santa Clara County is home to more than 4,000 registered sex offenders -- 535 of them registered as transients who are required to re-register every 30 days. But officials said that does not always happen.
A Sexual Assault Felony Enforcement task force on Thursday morning began a two-day sweep in Santa Clara County to try and track down 20 transient sex offenders who haven't re-registered.
"They have lookouts and when we walk in they signal to the others law enforcement is here and they all leave and then at night they'll be back," said Kelvin Mah, Santa Clara County Sheriffs Department.
During the search deputies found several people who are not sex offenders, but are wanted for other crimes, such as drug-related crimes and weapons violation.
"While we are out here focusing on sex offenders who are transients, we are cleaning up the community," said Deputy Kurtis Stenderup of the Santa Clara County Sheriffs Department. "Many of the people we encounter have narcotics or are on parole."
View more in Marianne Favro's video report above.