Problems with the devices included defective electronics that generated false alarms and batteries that wouldn't hold a charge, according to the Probation Department audit, obtained by a public records request from the Times (http://lat.ms/1dJHX6e ).
One felon had to have his faulty GPS device replaced 11 times in a year, the audit showed. At one point, his whereabouts were unknown for five days.
"If you have faulty technology, that is a recipe for disaster," said Reaver Bingham, deputy chief of the Probation Department.
Sentinel Offender Services, the contractor that provides the devices, said most of the problems were caused by untrained probation officers or felons who failed to follow directions. The company said county employees sometimes mistook dead batteries for malfunctioning equipment and that homeless people released on probation were inconsistent in recharging the devices.
The law requires that the devices be reviewed monthly and that the contractor providing them be evaluated once a year. But officials told the Times that Sentinel's work wasn't reviewed until similar problems with its devices were reported elsewhere. Orange County canceled its contract with the company after discovering problems with both its tracking devices and home detention systems.
California's Jessica's Law, adopted in 2006, requires that GPS tracking devices be used on high-risk sex offenders who are released from prison. The technology is also becoming increasingly popular for use with other criminal offenders. San Bernardino County is using GPS devices to track homeless felons after their release. Los Angeles County uses them on repeat sex offenders, violent gang members and people who have violated restraining orders.
They are usually strapped to a person's ankle and, if working properly, should update that person's location every minute. The device also should alert authorities if the wearer tampers with it, tries to flee or goes to a location they have been prohibited from visiting.
According to the audit, one probationer told investigators his GPS monitor had to be replaced four times in the first month after his release from prison. A Sentinel employee told auditors that another person's monitor never worked.
In some cases, the audit discovered, probationers were released without tracking devices because the company had run out of functioning equipment.
Sentinel complained to auditors that the county did not respond to its requests for more direction. The company also said it began holding training sessions for probation officers in October and is replacing its GPS devices with newer models.