Sex Offenders' GPS Devices Not a Silver Bullet, States Say

California, Arizona, Connecticut  and other states discover that problems with GPS monitoring of sex offenders beg a more thoughtful approach.

by / January 31, 2009

GPS monitoring -- embraced as a simple technological solution for tracking the whereabouts of convicted sex offenders -- is proving to be something less than a silver bullet for state and local public safety agencies.

Convinced that GPS monitoring was the answer to the sex offender problem, judges and lawmakers began mandating the technology for high-profile parolees. Beginning in 2005, the technology was widely deployed as means to ensure that offenders complied with the terms of their release, such as staying a safe distance from schools or a victim's home.

Monitoring systems typically consist of a GPS receiver/portable tracking device, radio frequency transmitter, stationary charging unit, cellular telephone and computer software to review GPS data. The devices allow officials to track the parolees' whereabouts -- when everything works properly and when offender cooperates.

But there are problems with the way the technology is used and monitored. False alarms number in the thousands in some jurisdictions, straining manpower and casting doubt on the viability of GPS as a tracking tool for high-profile felons.

In Arizona, a 2007 legislative study found more than 35,000 false alerts by 140 subjects wearing the GPS-monitoring devices.

In California, the percentage of transient parolees, those who've been declared homeless, has increased by 900 percent since a law was passed that included GPS as part of the solution. Now, officials say, they're guessing about where the offenders are because more have become transient and the GPS monitoring can be unreliable, especially when the offenders lack real housing where they can charge the devices.

And in Connecticut, officials are pushing for a state-run monitoring facility to keep track of offenders being monitored by GPS after numerous false alarms involving several subjects, including one whose case prompted action.

Though public safety officials typically agree that GPS is a valuable tool, they say it's not a replacement for personal contact with the subject, his co-workers, family and friends that keeps the offender honest.

Released, Arrested, Released

Connecticut's move for a proposed monitoring facility resulted from a recent re-arrest of a sex offender.

After serving 24 years in prison for multiple sexual assaults, David Pollitt was released and put on probation in September 2007. Pollitt was confined to his sister's residence and required to wear a GPS anklet that tracked his whereabouts. In September 2008, Pollitt was re-arrested after allegedly violating conditions of his parole by leaving the property.

However, Pollitt and his lawyer contended that the GPS unit provided a false alert. In fact, they contend that during the one-year period after Pollitt's release, the unit sent more than 40 false alarms.

Pro Tech Monitoring Inc., a subcontractor for G4S Justice Services, eventually wrote a letter to the court that said it couldn't say conclusively that Pollitt had left the property, according to Pollitt's lawyer, John Kaloidis. Two days after Pollitt's arrest, the warrant was withdrawn.

"A tech went to the home where my client is and said there was a problem with the device," Kaloidis said. "[The signal] bounces off cell phone towers, and there are certain points it can bounce off. It didn't find the street where my client was and bounced him to the next street over."

Pro Tech didn't return phone calls and e-mails to discuss the case.

There were also other problems with the tracking device and its monitoring that added up to the false alerts.

Once, Pollitt was plotted on GPS to have been more than 400 feet from his residence at 12:59 p.m. Just seconds later, he was plotted at the residence, according to a report by the Court Support Services Division of the Connecticut Judicial Branch.

"It would happen in the middle of the night when he was sleeping," Kaloidis said. "The family had to put the phone near his bed because they were tired of being awakened by probation officers saying, 'Dave, where the hell are you?'"

The tracking device assigned to Pollitt is a two-piece unit consisting of a transmitter (a battery-operated GPS device worn on the ankle) that emits a radio signal to a portable-tracking device (PTD), a small box that's worn on the offender's waist. The PTD receives radio signals and position information from the GPS device through satellites. The PTD transmits location information to a monitoring station in real time through a cell phone.

Pollitt's unit was programmed to sound an alarm if he ventured outside the vicinity -- a Pro Tech representative marks the property's perimeter into the PTD to program the area in which the parolee is required to remain.

The subject is responsible for wearing the PTD on his belt and for keeping batteries in the transmitter. A dead battery or putting the PTD in a pants pocket would send an alert. Bill Carbone, executive director of the Connecticut Supreme Court Services, said those issues could have caused some of the alarms. "But I don't think you can just point to the one area where he wasn't wearing the unit in the place where you get the best service. This happened a lot of times."

Kaloidis said the devices might not have been programmed correctly. "I think when they went to the house they didn't properly calibrate the machine," Kaloidis said. "The four corners of the property weren't marked."

Then there was what Carbone characterized as impermissible actions by Pro Tech staff. "I would call it unacceptable that we would get a verbal then a written response [confirming that Pollitt had left the property], then two days later have the company reverse it," he said.

A Connecticut Court Support Services report acknowledged a general misconception about GPS and sex offender supervision, and frustration for law enforcement officials who must deal with voluminous false alerts.

The report acknowledged that probation officers' work hours don't extend into the nighttime and weekends, and probation officers must respond to alerts while off duty. If the officer is out of cellular range or not near a computer, he or she may be unable to review the tracking data.

The report recommends assigning a secondary officer to high-profile cases to cover for the primary officer when he or she is unavailable. It also recommended a monitoring center to screen GPS and electronic-monitoring data and alerts at all times.

"We are determined to have some sort of call center in Connecticut that will monitor the offenders, receive the initial alert and serve as a screen prior to the officer knowing about the alert so they aren't bothered on a 24-hour basis," Carbone said, acknowledging the obvious waste of manpower spent tracking false alerts.

Understanding its Limitations

All sources interviewed for this story said GPS is a legitimate tool for law enforcement, but its limitations must be understood, and it must be used correctly. "It's got to be centered in the context of all the other information available to the officer, including the reports from treatment, family and so forth," Carbone said.

Policymakers should understand that having a GPS device on subjects doesn't mean they're monitored all the time. "A lot of people think if you're on GPS somebody is sitting at a computer and they know your whereabouts all the time," Carbone said. "They're not aware of the influence of weather and other interferences with the system and the

cell tower issues."

The Connecticut Court Support Services report noted that in an ideal environment GPS can be very accurate, but in difficult topography or in bad weather, tracking errors and signal loss can disrupt accuracy and consistency.

California relies heavily on GPS monitoring, despite the false alarms and failures, since a new law was put into effect that tries to keep sex offenders away from schools.

Jessica's Law prohibits convicted sex offenders from residing within 2,000 feet of a school or park. In November 2008, an appeals court ruled that the law amounts to additional punishment, although the law was left in effect for the time being.

Critics contend that the law is making sex offenders harder to track because some, either intentionally or not, are becoming homeless.

And the trouble with homeless sex offenders is there may be nowhere to recharge the unit's batteries. "GPS units need to be plugged into a wall," said Robert Coombs, director of public affairs for the California Sex Offender Management Board. "So it is a real problem that these guys have gone transient, and unless we let them into our public libraries or Starbucks or any other place where they can plug in, we're not going to be able to maintain this problem."

Before the 2008 law passed, 88 registered sex offenders were homeless. That number has risen to more than 1,000 since then, and it's because the law focuses on GPS, Coombs said.

Officials say the offenders are being tracked with the GPS, but critics say that's not enough. "Those of us who work with victims and offenders know that just because you know where a guy is, doesn't mean you know what he is doing," Coombs said. And that's assuming the devices are working correctly, and they sometimes don't, he said.

"This is actually the melding of two technologies," Coombs said. "One is GPS, which is essentially getting that signal from satellites, and the other is cellular technology, which is then transferring that data to the nearest cell phone tower. The weaknesses of those two technologies are compounded by bringing the two together."

Coombs said parolees can venture out of the satellites' range by entering buildings or a dense urban location. "Places like schools, hospitals, government buildings," he said. "You walk into the Capitol building here in Sacramento (Calif.) and you lose satellite reception."

Coombs said there have been instances in California where an offender was on a train or bus heading to a mandated treatment facility and his satellite reception was lost.

Additionally the offender is counted on to charge the device's batteries and make sure he's wearing it on his belt and not in his pocket. "These are folks who we've already identified as having trouble following rules or schedules," Coombs said. "They may intentionally fail, because by not charging it, they know they're not being tracked. 'If I don't charge this thing for two hours, there's no evidence of where I've been.'"

It's a Fad?

Sources said policymakers have made promises about the technology that won't hold up. "In our business, they invent these things, they advertise and the attorney sells the judge, 'Rather than put my client in jail, put him on the GPS,"' said Mike Goss, deputy chief of the Maricopa County, Ariz., Adult Probation Department. "It's a snazzy thing; it's become sort of a fad."

In Washington state, there has been resistance to GPS monitoring. In 2006, the Washington Association of Sheriffs and Police Chiefs opposed proposed legislation -- which passed -- to expand the use of GPS because of experiences with faulty readings when offenders move inside steel buildings,

tunnels or outside when it's snowing, according to Don Pierce, the association's executive director.

"We believed, and still believe, that GPS monitoring should be used when it's appropriate and not simply across the board," Pierce said. "We were concerned, and still are, that GPS monitoring is viewed as a panacea and will prevent future crime. It isn't, and it won't."

The belief that GPS monitoring could replace any other types of supervision, such as visits from the probation officer, conversations with family, counselors and so on, is a dangerous one. "It's best used as a corroboration tool," Coombs said. "When you have a routine parole meeting and the guy says, 'Well, I haven't been in a certain location,' [such as an exclusion zone] you can verify that."

But the technology won't keep people out of trouble if they're prone to trouble. "It's only as good as the approach used to implement it," Coombs said. "If you think the technology is going to protect children because [the offender] can't go near schools, then you forget that children exist in places other than schools."

Arizona eschewed the two-piece units in favor of a one-piece device and has had fewer false alarms, Goss said. "Now, the one piece that straps on the leg is a real small unit and it's all self-contained."

In late 2008, Rhode Island was about to launch a GPS-monitoring program that might be more accurate than technology being used now. It was pioneered by a local private company.

The consensus is that GPS has a role, but its limitations must be understood. "There's a very legitimate and important role for GPS, but it's one tool in the toolbox," Carbone said. "Policymakers need to be better informed so there's not a rush to use GPS because they think it's like LoJack."


Follow Government Technology on Twitter.

Jim McKay, Justice and Public Safety Editor Justice and Public Safety Editor