Legislators are crafting a bill that would spell out the parameters for installing digital technology to track suspected criminals.

Small devices that link up to “global positioning systems” can help law enforcement track a suspect and build a criminal case, but Representative Rick Olson of Des Moines says the rules of engagement need to be tightened for how, where and when the devices may be used.

“Typically it’s going to be on a vehicle, but it could be on the heel of a shoe,” Olson says. “It could be in your Samsonite luggage, you know, whatever you might carry with you.”

Representative Kim Pearson of Pleasant Hill says legislators also aim to set a limit for this kind of GPS surveillance, like no more than 30 days.

“This is not going to be carte blanche for them to just put this GPS where ever they want it, for as long as they want it there,” Pearson says.

Another concern for Pearson and other lawmakers is making sure judges who issue warrants that let police to into a home or business install a GPS device determine any “confidential informants” in such cases are credible. Representative Olson says it does make sense, however, to use GPS units to track suspects.

“It’s a more efficient way to do police work,” Olson says. “Rather than assigning a detective or a police officer to follow you around 24/7, like you used to see on TV, it’s now going to be electronic.”

A bill on the subject has cleared the House Judiciary Committee, but Olson, Pearson and others are still adjusting language in the bill before it comes up for debate in the full House.