A Dorchester man will spend the rest of his life in prison for shooting his girlfriend’s ex-boyfriend to death during an argument in the woman’s Jamaica Plain home two years ago, Suffolk County District Attorney Daniel F. Conley said.

A Superior Court jury this afternoon convicted GREGORIO “MIKEY” LOPEZ (D.O.B. 9/3/90) of first-degree murder for shooting 32-year-old Shoughan Morgan in the chest, killing him, his girlfriend’s Mozart Street residence on March 11, 2009.

Judge Patrick Brady waited just a few minutes before sentencing Lopez to the mandatory sentence of life in prison without the possibility of parole. At the defendant’s request, Brady allowed a one-week stay of execution, allowing him to recover his belongings from the Nashua Street Jail, where he has been held since his arraignment about two weeks after the murder.

Brady also heard a brief statement from Morgan’s brother, who told the court that his family consisted only of his mother and four boys – “and now one of us is gone.”

“These two years have been the hardest thing we’ve ever had to deal with,” he continued. “I’m just thankful this day is here, but there’s a part of us that’s always going to be gone and we’ll never get it back.”

During the week-long trial, Assistant District Attorney David Fredette of Conley’s Homicide Unit proved that at about 1:30 on the morning of the shooting, Morgan entered his ex-girlfriend’s bedroom and found Lopez – the woman’s new boyfriend – in her bed. The two men became involved in a verbal altercation, and the woman led Morgan out of the room and into the hallway landing outside of the apartment to have a private conversation.

Lopez stayed in the bedroom and used his girlfriend’s cell phone to make several calls, and indicated to a witness that he was going to get a weapon. The defendant left the apartment through the back door and returned a short time later with a shotgun.

Fredette proved that Lopez walked down the hallway and opened the front door, where he found the victim still talking to his girlfriend, and fired a single shot into Morgan’s torso, causing fatal injuries to his internal organs and ultimately killing him.

After the shooting, evidence and testimony showed, the defendant kicked the victim and gestured at him before fleeing the apartment.

Witnesses at the scene who knew Lopez later identified him to police as the shooter.

Catherine Rodriguez was the DA’s assigned victim-witness advocate. Lopez was represented by attorney Bruce Carroll.