With traditional GPS or RF-based systems, multiple devices are employed to vary monitoring intensity. For instance, these systems typically require offenders to don an ankle bracelet then place it into a home unit when coming or going to ensure curfew restrictions are followed. In passive monitoring cases, traditional systems require offenders to wear a personal tracking unit (PTU) in addition to an ankle bracelet when leaving the home. When the offender returns home, the PTU is plugged into a docking station then follows instructions to submit his location history via landline phone. The offender must carry yet another device, a transmitter, to accomplish active monitoring. This transmitter picks up location data from the PTU and transfers the information every couple hours over a cellular network.
Omnilink's system accomplishes these monitoring intensities with a single, 5.3-ounce ankle bracelet, equipped with a rechargeable battery that lasts up to 3 days in intensive supervision and up to 21 days in low-usage scenarios. "We have a true single-unit device that you can move through different levels of monitoring without the offender knowing it," Aninye says.
A single, sealed system also cuts down on maintenance, says Butler, who notes the agency's previous RF systems were not sealed. "When we'd get them back, the turnaround time would be days because we had to put them into a fumigation chamber," he says. "We essentially had to 'bug bomb' them." Las Vegas officers simply put the Omnilink system into a dishwasher, supplied by the company, to clean the bracelets.
"There really is no maintenance involved," he says. The department keeps devices charging at all times, so they go out fully charged. The old units required officers to cut the straps to remove them and then replace the straps. The Omnilink system has two pins that pop out to remove the device and pop back in for reuse.Monitoring offenders wherever they are
Urban canyons and bodies of water have traditionally presented barriers to GPS and RF offender tracking systems. But Omnilink's device utilizes a precision engine that allows it to locate and track offenders in most impaired environments, including tunnels, armored vehicles, subways, and in and around buildings or water. "Unlike pure GPS systems, our system uses wireless networks to augment the GPS," says Aninye. In short, the system relies on GPS tracking when it's available, but when it's not it, tracks offenders via cellular networks.
Unlike most GPS devices that require line-of-site to satellites circling above, Omnilink trails offenders with or without GPS line-of-site. In fact, Omnilink systems have traced offenders in New York City subways and Las Vegas casinos. This is a boon to law enforcement, especially in Vegas, where Aninye says "the way the hotels are connected, other systems lose site of an offender — the offender went in one end and couldn't be tracked anymore until he came out. With our solution, we know where the offender is every single minute."
While GPS and RF-based systems are prone to error, Omnilink's cellular and GPS capabilities counterbalance each other for greater location accuracy. When line-of-site is available, the system relies on GPS first then corrects any deviations through the cellular network. With the wireless tracking, the system recalculates location as soon as line-of-site becomes available to ensure the location is accurate to within 12 to 50 feet.
Butler describes the system's accuracy with the following story. Officers recently found one of their tracked offenders was a runner, meaning he wasn't where he was supposed to be and officers were unable to make contact. Officers kept tabs on this offender throughout the city of 2-million residents and caught up with him at a relative's home. "Before, all we knew was if they were at home or away from home," Butler says of the agency's previous landline-based RF system. "Once they were away from home, we had no idea where they were."Pinpoint location software
The Omnilink Focalpoint software used within the device is based on a management-by-exception architecture, which means officers no longer need to watch dots on a map to figure out what offenders are doing. Instead officers define supervision rules, specify offender schedules and establish specific alert criteria on an offender-by-offender basis. They can then receive alerts via fax, e-mail, pager, text message or telephone call whenever an offender violates these predetermined conditions.