A little more than a year ago, California quietly began conducting tests on the GPS monitoring devices that track the movements of thousands of sex offenders. The results were alarming, says the Los Angeles Times. Corrections officials found the devices used in half the state were so inaccurate and unreliable that the public was “in imminent danger.” Batteries died early, cases cracked, reported locations were off by as much as three miles. Officials also found that tampering alerts failed and offenders were able to disappear by covering the devices with foil, deploying illegal GPS jammers or ducking into cars or buildings.
The state abruptly ordered parole agents to remove every ankle monitor in use from north of Los Angeles to the Oregon border. In their place, they strapped on devices made by a different manufacturer — a mass migration that left California’s criminal tracking system not operational for several hours. The test results provide a glimpse of the blind spots in electronic monitoring, even as those systems are promoted to law enforcement agencies as a safe alternative to incarceration. The flaws in the equipment raise the question of whether the state can deliver what Jessica’s Law promised when voters approved it in 2006: round-the-clock tracking of serious sex offenders.