Law enforcement technology helped find Va. shooter

It is a story that continues to send shock waves around the country, a news crew gunned down on live television.

But as the suspect attempted to get away, a new piece of law enforcement technology used by state troopers in Virginia may have been key in catching 41-year-old Vester Flanagan.

It's technology that is used nationwide, including here in Arizona.

"Right now the machine is reading as we pass by, if it was a vehicle of interest it would send me an alert right away," said Tempe Police Officer Mark Regester.

Officer Regester says he gets alerts from his automatic license plate reader, and they are instant.

"Basically it's a tool for our investigators to put pieces of a puzzle together as information comes in, they know who they are looking for, and they are saying hey do they drive this vehicle," said Regester.

Commonly known to law enforcement as ALPR this is the same tech used by Virginia's troopers to track the shooter.

"The plate became known and the trooper in this case put the information into the system, it says hey it just went by, so that is how it works," said Regester.

The model the Tempe Police Department uses relies on three cameras mounted on the roof of the patrol car to read all of the information.

"That is the exact reason we have it, when somebody commits a crime, somebody we're looking for, somebody we need to find," said Lieutenant Mike Pooley.

Lt. Pooley says Tempe has 8 units with ALPR equipment installed, five of them are patrol cars. The cameras take two images of the plate, and one of the back of the car. Police say the main goal is to find violent criminals.

"The officers get the information, then they verify it, they have to figure out who the registered owner is," said Pooley.

Detectives build hot lists which are updated four times a day containing suspects they're looking for, but just like in Virgnia the officers can add information at any time.

The information gathered is stored for 180 days for investigate purposes and then purged. Several agencies use systems similar to Tempe's.