When police recover a gun used in a crime, a technology called thermal imaging helps investigators figure out how recently it has been used and how recently it was even touched.


In court cases, police were viewed as the officers who found the guns, not experts on the science, and for years courts did not allow the use of thermal images as evidence.


That changed in 2008 when police and prosecutors recruited graduate students from the Massachusetts Institute of Technology to help explain to judges and juries the science of the device. That’s the year of the first convictions involving the technology.


Last week, Suffolk County District Attorney Daniel Conley honored Adam Wahab and Priam Pillai, the two MIT students who for years have been the county’s expert witnesses on the technology.


“We expect to see a lot more of them in the months to come,” said Jake Wark, spokesman for the district attorney’s office.

Wark cited numbers that showed an increase in the pending cases that use the thermal imaging devices.

Boston Police Sgt. Joel McCarthy, who oversees the use of the device by police units, said it’s proved vital for recovering ditched guns and convicting the suspect.

“Even district attorneys who have never used it in a case are asking if there are thermal pictures,” he said.