A Suffolk County Gun Court jury yesterday convicted a Roxbury man of carrying an unregistered firearm and six rocks of crack cocaine after being chased by a sharp-eyed officer who first saw his associate with a knife, Suffolk County District Attorney Daniel F. Conley said.

ALPHONSO WESLEY (D.O.B. 8/22/89) of all charges – unlawful possession of a firearm, unlawful possession of ammunition, and unlawfully carrying a loaded firearm, and possession of a Class B substance with intent to distribute – for his Feb. 2 arrest near Dudley station.

Assistant District Attorney Nicole Rimar of Conley’s Gun Prosecution Task Force recommended that Wesley serve a total of five years in jail with 2½ years committed and a second 2½-year term suspended for a five-year probationary period. Rimar further recommended that Wesley be ordered to stay away from the Dudley Square area, undergo drug testing, and be supervised by the Office of Community Corrections.

Judge Thomas Horgan sentenced Wesley to two years behind bars with a second two-year term suspended for five years, declining to impose the recommended conditions.

“Every gun conviction takes a potential shooter off the street,” Conley said. “There’s a mandatory 18-month sentence for unlawful firearms possession in Massachusetts, and every person who carries a gun on our streets should know we routinely seek jail terms longer than that.”

During the three-day trial, Rimar introduced evidence and testimony to prove that Wesley was among a group of young men at Dudley who drew the eye of a Boston Police officer on routine patrol. When the officer engaged the group in conversation, he noticed that one member of the group appeared to have a large knife clipped to his belt. When the officer exited his cruiser, Wesley – who was not the one carrying the knife but who had thus far refused to meet the officer’s eyes – took off in a sprint.

The officer noted that Wesley was running with his right arm swinging free but his left arm stiff against his side. Recognizing that to be one of the “armed gunman characteristics” as described by his law enforcement training, the officer gave chase.

The suspect with the knife escaped, but Wesley was apprehended at 125 Madison Park Ct. After seeing him rise from a crouch near a parked car, officers checked the area and recovered a .380 caliber Davis Industries semiautomatic firearm loaded with six rounds in the magazine and one in the chamber. From Wesley’s pockets, the officers recovered two small bags of marijuana and one bag containing six smaller bags that each contained a rock of crack cocaine.

Boston Police deployed a thermal imaging device, which records heat the same way a conventional camera records light. Several thermal images of the firearm in situ revealed it to be warmer than its surroundings; at trial, Rimar used these images as evidence that the gun’s metal frame had retained the body heat of the person – namely Wesley – who had carried and discarded it.

During the booking process, Wesley was heard to say during a phone call that “I got popped …. I tried to, but they found it.”

The Suffolk County Gun Court is a dedicated set of sessions for gun possession cases and collateral offenses established on Conley’s initiative four years ago. The process of adjudicating those cases has been streamlined such that a case that once took a year or longer to go to trial is now disposed in an average of 146 days; Wesley’s case was adjudicated in just 134 days.

The overall conviction rate has remained at 80% or higher, rising to 89% in 2009, and appellate prosecutors assigned to the Gun Court have won more than 80% of their challenges to suppression orders, bringing guns back into evidence and setting the stage for trials or guilty pleas.

Wesley was represented by attorney Amanda Sheehan.