Is GPS tracking a better way?

I spoke at a sentencing seminar this morning, and the terrific speaker after me reviewed all the reasons why residency restrictions for sex offenders likely endanger, rather than enhance, public safety.  (Astute readers will recall that Iowa's prosecutors, who have the most experience with these laws, came to this conclusion long ago as documented here.)   Beyond the public safety consequences, the California experience with residency restrictions in Proposition 83 (details here and here) spotlights that these laws always engender copious litigation.

But another facet of Proposition 83 may not be quite as bad, though it is sure to also stir up some litigation: GPS tracking of certain offenders.  Thanks to Crime & Consequences, I saw this interesting article at Wired News about GPS monitoring, titled "Attack of the Perv Trackers."  Here are parts of a fine piece:

Just a few years ago, satellite tracking of convicts was a newfangled alternative to house arrest.  Now, the number of American ex-offenders tracked through GPS-equipped ankle bracelets will likely triple to more than 30,000, thanks to the passage of a California ballot measure. California's Proposition 83, which easily passed Tuesday by a margin of 70 percent to 30 percent, requires many convicted sex offenders to be monitored by GPS for life....

At least 11 other states have recently considered GPS tracking legislation, with some inspired by the 2005 murder of a Florida girl, allegedly by a registered sex offender.... But there's a hitch: The ankle bracelets -- usually accompanied by digital-pager-size transmitters -- are hardly criminal-proof.  Convicts can easily cut the bracelets off and run away as their probation officer gets an alarm and tries to contact the local police. For health reasons, the bracelets aren't designed to be permanent.

"GPS will not prevent a crime," said Steve Chapin, CEO of Pro Tech Monitoring, a manufacturer of GPS tracking devices. "It's a crime deterrent. It has proven to be a good tool, but you can't oversell it -- there's no physical barrier that it creates that can prevent a crime." Chapin said his Florida-based company tracks about 10,000 people, and he thinks other companies track a few thousand more. Offenders wear an ankle bracelet -- Chapin said it can be hidden under a sock -- and keep the transmitter nearby. 

There are an estimated 63,000 to 90,000 sex offenders convicted of felonies and misdemeanors in California. According to Chapin, it's possible that about 20,000 of them will need GPS monitoring under the new law.  Chapin expects the state to adopt "active" monitoring, which tracks offenders in real time and sends out alerts if they go somewhere they're not supposed to, such as a school. The alternative is "passive" tracking, which produces reports about where offenders have been, not where they are right now.  Currently, Pro Tech charges $6 to $8 a day for active monitoring, and $4 to $5 a day for passive monitoring, equipment included. At that rate, California can expect to fork out between $80,000 and $160,000 per day to watch its sex offenders.... 

GPS tracking technology allows users to create "geofences" to mark forbidden "hot zones."  The monitoring systems can even be programmed so that alarms only go off if an offender spends a certain amount of time in an outlawed area instead of, say, simply driving through it at high speed on the way to somewhere else.

GPS tracking has its critics. The American Civil Liberties Union has been skeptical, although at times intrigued by an alternative to incarceration.... [A] new study of more than 75,000 Florida convicts found that both GPS monitoring and old-fashioned, house-arrest electronic monitoring (the kind Martha Stewart endured) made convicts more likely to toe the line.  "Our conclusion is that it does help protect public safety, that these offenders are less likely to get in trouble," said study co-author Kathy Padgett of Florida State University.