Electronic devices tell where you are and if you’ve been drinking

The long arm of the law is getting longer thanks to new electronic monitoring devices that show where people under court control are going and what they’re drinking.

Global positioning satellite signals and cellular telephones allow authorities to track the precise locations of criminal defendants they monitor, even how fast they drive. GPS monitoring systems can set off alarms and send pager warnings if someone under a no-contact order enters a prohibited zone, for example, or leaves a confinement zone.

These relatively new systems allow suspects to retain much of their freedom while awaiting trial, but help ensure that their conditions of release are obeyed.

That’s a lot different from traditional “RF,” or radio frequency, monitoring. RF monitoring confines a person to a specific location, usually their home, during designated hours. It uses a conventional telephone line and short-range radio signals. If a transmitter strapped to the detainee’s ankle gets out of range of a receiver, that fact is recorded and reported by phone.

Although not foolproof, the RF system is tried and true.

GPS monitoring, on the other hand, is only as dependable as the cellular telephone service it uses. It doesn’t work in cellular dead zones or where hills or tall buildings block satellite signals.

Even with so-called “active monitoring,” in which GPS location signals are reported every few seconds over a cellular telephone network, there is little chance of preventing an escape or a new crime. Those who don’t want to obey the rules can simply throw away their transmitters and flee.

That will transmit an alarm, but “you can never get anybody to respond quick enough to stop whatever was going to happen anyway,” said Brett Sobosky, custody manager at Spokane county’s Geiger Corrections Center.

Geiger uses an electronic monitor called the Sobrietor to keep people from drinking. The Sobrietor requires breath tests as often as hourly, using a voice-recognition system and several other high-tech safeguards to ensure the tests are valid.

The private Second Watch monitoring service uses a device called SCRAM — Secured Continuous Remote Alcohol Monitoring — to detect ethanol fumes released through the skin when people drink, as well as the skin temperature increase that accompanies alcohol consumption. The device uses an infrared sensor and other methods to detect tampering.