The new law, which goes into effect July 1, comes amid heightened privacy concerns over the role of government surveillance programs, including the National Security Agency's collection of email and phone records.
In Indiana, much of the debate has revolved around a suitcase-sized monitoring device known as a Stingray, which masquerades as a cellphone tower and can scoop up call and location data from hundreds of nearby cellphones in real time.
An Indianapolis Star investigation revealed in December that the Indiana State Police had purchased the device for $374,000. But neither state police nor the governor would say exactly how officers use the device, or whether they obtain a search warrant before turning it on.
House Bill 1009, authored by Rep. Eric Koch, requires law enforcement officials to establish probable cause and obtain a court order before electronically tracking the location of mobile phones or other cellular devices in real time.
There is an exception for "exigent circumstances," such as when people's lives are in immediate danger. But even in those cases, officers would be required get a court order based upon a finding of probable cause within 72 hours.
The probable cause language is important because it requires detectives to convince a judge that there is reason to believe a crime may have occurred.
A joint investigation by The Star and USA Today found that in many states, cellphone data can be obtained with a court order that simply requires detectives to show that it would aid in an investigation. That's a much easier standard to meet than probable cause.
Read the full story at the Indianapolis Star