PITTSBURGH (KDKA) — More than 1,100 registered sex offenders live and work in Allegheny County and 43 of them are now wearing monitoring devices as a condition of their parole.

District Attorney Stephen Zappala blames the nature of the crime for the need to better track these offenders.

“Because the psychology of the crime of the criminal actually is, they will re-offend and so we’re looking at persons who are recidivists,” Zappala said.

The offenders are monitored by places like Guardian Protection Service. The system uses GPS technology.

As long as the offenders stay in the inclusion area, they’re OK, but if they travel into an exclusion area, police are notified immediately.

“Exclusion zones for example [are] schools, daycares, playgrounds, facilities where children congregate for those sex offenders,” John Hudson, a security consultant, said. “We’ve identified in their red zones. If an offender with a device goes into one of the red zones, an exclusion zone, we’ll be notified immediately.”

“On the policing side, it’s really important for the community to know that once these bracelets are put on these guys the police can watch them 24/7,” Zappala.

KDKA’s Bob Allen tested the system by putting on a bracelet and driving to the Woodland Hills High School parking lot in Churchill.

The system tracked him the whole way down the Parkway East to the school. Within 30 seconds after driving on school property, the pager went off warning him he was in an exclusion zone.

The GPS system worked. In a real situation, any convicted sex offender wearing a bracelet and caught in one of the red zones would be arrested and possibly sent back to prison.

“These particular offenders we know where they are 24/7, the police patrol with purpose,” Zappala said. “If you have children especially, I think that’s really significant.”