A bill in the Senate has triggered a debate between law enforcement officials and privacy advocates.
The legislation would limit the length of time Vermont police and prosecutors can retain millions of records of license plate scans collected statewide.
David Cahill is the executive director of the Vermont Department of State's Attorneys and Sheriffs, and he told the Senate Judiciary Committee Wednesday that license plate readers can be helpful in catching dangerous criminals.
"License plate readers are particularly useful to us from a prosecution perspective in major cases like homicides," says David Cahill, the executive director of the Vermont Department of State's Attorneys and Sheriffs.
Cahill told the Senate Judiciary Committee on Wednesday that police could use stored data from license plate readers to determine where a suspect's vehicle was in around the time a murder took place. He said it could help prove that a person's alibi was false or be used to eliminate them as a suspect.
But there is no evidence that Vermont police or prosecutors have ever used license plate data to solve a murder.
In fact, in 2013 and 2014 combined, there are only five or six cases in which license plate data was instrumental in an investigation. (One federal case may or may not have used the data in 2013, but officials refused to release details). Two missing persons were found with the technology in 2014, and two stolen cars were found using license plate readers in 2013. In another 2013 case, the Department of Motor Vehicles used license plate reader data to help solve a case of internal fraud.
And there are serious privacy concerns.
"I think the one thing that everybody can agree to is that a person's right to privacy is violated whenever government records movements of individuals who aren't subjects of investigation," said Allen Gilbert, the executive director of the Vermont chapter of the American Civil Liberties Union.
And that's what the technology does, on a massive scale.
In the 18 months immediately preceding Jan. 1 of this year, Vermont police collected time-and-place snapshots of vehicles more than 8 million times.
Of those 8 million scans, there were just 39 instances in which data was released to investigators around the state last year as part of an investigation.
The rest were never considered relevant to any data requests from officers in the field.
A bill in the Senate would dramatically shrink the amount of time police could hold onto that data - from 18 months to just 24 hours.
State police Lt. Kevin Lane oversees the statewide license plate database. He said that time limit would be a major blow to the system's ability to help in investigations.
"Its capability to be used in a criminal investigation or a missing person case would be severely limited to almost nonexistent," he said. "It would really undermine the whole program to ... go to 24 hours."
Lane said that of the 39 times data from the database was released to investigators, 28 took place after 24 hours. This means if the proposed legislation was in place in 2014, there would have been just 11 releases of information.
He also said one of the two "success stories" featured in the most recent annual report on the program would have been possible even with the 24-hour retention period.
Limiting retention times to 24 hours, Lane said, would relegate license plate readers for use mostly in traffic enforcement.
That use of the technology is slightly different in that the license plate readers are constantly scanning vehicles that pass by equipped police cruisers and checking those plate numbers against a "hot list" of cars with expired registrations or cars that are registered to suspended drivers. If a hot listed car passes a cruiser with a license plate reader, the cruiser's in-car computer alerts the officer, who can then make a stop.
Captain Jake Elovirta is a Department of Motor Vehicles enforcement officer. He said license plate readers have been especially useful for this purpose.
"Definitely with the LPRs [License Plate Recognition systems] you've seen a spike in the number of criminal DLSs [Driving with a Suspended License] and civil suspension tickets that are issued by law enforcement because the LPR is now identifying those vehicles to the officer," he said.
But numbers from the DMV itself don't support that claim.
In the five years before license plate scanners were introduced in the state in 2009, DMV statistics show the state averaged 8,614 citations for driving under suspension annually.
In the five years following that, as license plate reader technology proliferated in the state, that average fell by more than 1,000 - to 7,457.
Lawmakers must decide this year how long they want to allow police to hold onto license plate data, as existing legislation governing its use expires this year.
Senate Judiciary Committee chairman Dick Sears says he wants to shorten the retention period, but not so dramatically.
"I think 18 months is probably too long," he said. "My personal opinion is 24 hours is too short, but we'll see where it goes."
Chittenden County Senator Tim Ashe, who proposed the bill, said he'll likely have to settle for some middle ground, perhaps 30 or 90 days.
The bill contained other provisions related to privacy that aren't likely to be taken up this year, but he says it's important to raise the issue.
"If we're not careful before long, nothing will be private," he said. "There will be no such thing as a private life in Vermont or anywhere else, and you will not have a reasonable expectation that when you step foot outside your house, that you're living a life that's yours to know about alone."
