A gun-toting Dorchester man last week became the first Massachusetts defendant convicted by a jury that heard expert testimony on thermal imaging technology, which demonstrated that the gun he tossed into a snowy back yard had recently been carried by a person, Suffolk County District Attorney Daniel F. Conley said.

A Boston Municipal Court jury on Monday convicted JOSE E. RODRIGUES (D.O.B. 6/30/84) of all charges stemming from his January arrest for carrying a loaded 9mm handgun on Whittemore Street in Dorchester. Following his conviction, Judge Sally Kelly sentenced him to two and a half years behind bars.

“Science and technology are advancing every day,” Conley said. “Bringing those advances into the courtroom is part of our mission and our responsibility. The work that began with fingerprints at the turn of the last century and continued with DNA as we entered the new millennium isn’t slowing down, and neither are we. When it comes to making our streets safer, we’re going to use every single tool at our disposal.”

During a four day jury trial ending on Nov. 23, Assistant District Attorney Tonya Platt of Conley’s Gun Prosecution Task Force didn’t just call the Boston Police officers who chased Rodrigues through side streets and back yards – she also called Priam Pillai, a graduate student in mechanical engineering at the Massachusetts Institute of Technology, who testified as an expert witness on thermal imaging technology.

That technology, pioneered for military purposes and now used mainly as a firefighting aid, has been used by Boston Police since they purchased a Bullard TI Commander, which records heat output the way a conventional camera records light. Because a metal object carried by a person retains heat, a recently-discarded firearm – such as one tossed by a fleeing suspect – will appear lighter than its surroundings in the Bullard’s thermal image.

Though the technology has existed for some time, Massachusetts courts had previously refused to allow it as evidence until Suffolk prosecutors developed expert witnesses to testify regarding its accuracy. Toward that end, prosecutors reached out to experts in thermodynamics and related fields at MIT. Pillai, who holds a master’s degree and teaches classes at the Ivy League school, was selected as a potential expert witness after a rigorous evaluation of his professional, educational, and ethical qualifications.

Suffolk prosecutors then led extensive pre-trial voir dire and evidentiary hearings in a series of efforts to have him qualified as an expert witness. Those efforts were successful, and Pillai testified as a court-certified expert in heat transfer technology in the Rodrigues case and an unrelated 2008 bench trial. But for the prosecutors’ work to bring the thermal images and the science that supported them into evidence, Conley said, the jury would never have seen them.

“Television and movies can contribute to unrealistic or even impossible expectations when it comes to scientific evidence and testimony,” Conley said. “This case allowed us to go beyond the conventional and bring the cutting edge to bear.”

In addition to hearing from Pillai, jurors in the Rodrigues case also heard testimony from Boston Police who observed the defendant clutching his waistband as he walked along Whittemore Street on the evening of Jan. 12. When they inquired of him, Rodriguez bolted from their vehicle. Officers gave chase, losing sight of him briefly before spotting him with an arm outstretched as if having thrown something; they finally took him into custody in the side yard of a Glendale Street residence. Along his path of flight, they later recovered a 9mm semiautomatic Smith & Wesson handgun.

In addition to taking conventional photographs of the weapon, Boston Police deployed the Bullard TI Commander and took thermal images of the gun and the area around it. These were the images presented to the jury. It was under similar circumstances that JOSEPH RIVERA (D.O.B. 10/31/89), who tossed a firearm into a garbage can while fleeing police in May 2008, was convicted at a jury-waived trial on similar charges; the judge in that case specifically noted the importance of thermal imaging evidence and Pillai’s testimony to her guilty finding.

Rodrigues was convicted of unlawfully carrying a firearm, ammunition, and a loaded handgun in the Gun Priority Disposition Session, a specialized set of proceedings known as “Gun Court” and dedicated to the rapid prosecution of gun possession cases. Since its inception in 2006, Gun Court has been the venue for more than 500 firearms possession cases; it has reduced the average length from arraignment to disposition from longer than a year to less than six months while maintaining a conviction rate of about 86%.

Rodrigues was represented by attorney Timothy Bradl.