A Dorchester man convicted yesterday of his second firearms offense faces a mandatory state prison term when he’s sentenced tomorrow, Suffolk County District Attorney Daniel F. Conley said today.

A Suffolk Superior Court jury yesterday found DARREN DYETTE (D.O.B. 8/2/89) of unlawful possession of a firearm and unlawfully carrying a loaded firearm. At a second set of proceedings following the trial, Dyette admitted that he was the same individual convicted of those offenses in 2008, making him a second or subsequent offender and exposing him to a three-year minimum for his latest conviction.

Assistant District Attorney Matthew Feeney of Conley’s Gang Unit proved during the three-day trial that Dyette was one of two men who fled Boston Police when officers arrived at the basketball courts along Martin Luther King Boulevard to investigate fireworks on the night of July 3, 2010.

So anxious were the men to flee police that they ran into one another as they sprinted out of the courts and into the nearby Malcolm X Park. Dyette, wearing a white shirt, white ball cap, and dark sneakers with white laces, ran toward Dale Street, while the second man, wearing a blue top, ran toward Washington Street.

The man in blue made good his escape. Officers maintained visual contact with Dyette, however, and apprehended him near the intersection of Dale and Rockland streets despite his efforts to alter his appearance by dumping his shirt and cap into a trash can along his path of flight. Further testing by the Boston Police Crime Laboratory revealed Dyette’s DNA profile on both the hat and the shirt.

Also recovered from Dyette’s path was a .40 caliber Sig Sauer P229 handgun loaded with nine rounds in the magazine and one round in the chamber, ready to fire. Using a thermal imaging device, which records heat output the way a conventional camera records light, officers found that the firearm was much warmer than its surroundings – a sign that it had been carried very recently and still retained Dyette’s body heat.

Conley’s office pioneered the use of thermal imaging in gun prosecutions, winning the nation’s first conviction based on that science in 2008.

Dyette was represented by Daniel Solomon. Judge D. Lloyd MacDonald will sentence him at 11:00 tomorrow morning in courtroom 808 of Suffolk Superior Court.