The Boston Police Department reports arresting three men on murder charges for the shooting death of Shawn Borden, 41, shortly before 6 p.m. on Oct. 11 on Dorchester Avenue at Dix Street.

Borden is survived by his mother, Barbara, a civilian employee of the Boston Police Department.

Police say Borden was working on his car at the time he was shot and that 15 rounds were fired at him.

Charged with his murder are Tyshawn Cummings, 21, Tyshawn Sanders, 18, and Jamari Manning, 21, all of Dorchester. They were arrested Friday by gang and fugitive-unite officers and are scheduled for arraignment Monday in Dorchester Municipal Court.

All three were already known to police.

On Dec. 19, 2015, police arrested Cummings on gun charges after police spotted him coming out of a Norfolk Street house with what appeared to be a gun in his waistband.

His arraignment on the charges was delayed after he was arrested in court for allegedly beating up another man in lockup with him.

Earlier, he had been acquitted of charges of assault and battery with a dangerous weapon for a 2013 incident.

On April 19, police arrested Sanders after he allegedly crashed a car on I-93 while being pursued by officers investigating gunfire in the area of Fernboro Street. A 17-year-old in the car with him at the time was charged with illegal possession of a loaded handgun.

On Dec. 1 of this year, Manning was arrested on marijuana distribution charges on Gallivan Boulevard.