Four persons were shot and killed in three separate incidents in Washington yesterday and late Monday since The Post compiled a list of shooting deaths that have occurred this year.

In all cases, except one new case reported last night, the violence stemmed from domestic disputes, according to D.C. police.

Shortly after midnight, police said, Mamie Cashwell, 67, and her 18-year-old grandson, Keith Oberton, were shot and killed in the apartment they shared at 3986 Pennsylvania Ave. SE. sThe bodies were discovered by Larrel Peek, Cashwell's daughter, police said.

An arrest warrant for murder was issued for Cashwell's son, Clarence Edward, 36, of the same address. Late yesterday, police said that Culpeper, Va., authorities informed them that a man fitting Clarence Cashwell's description was found dead there, apparently killed in a traffic accident. D.C. police dispatched a homicide squad detective to Culpeper late yesterday to investigate.

In another shooting, police reported that Charles Ford, 25, was killed during an altercation inside his apartment at 2640 Wade Rd. SE. Ford, armed with a knife, was arguing with his wife when one of four men visiting him at the time pulled a gun and shot him in the chest and side, police said. Two arrests were made, but other details were not immediately available.

About 7:15 p.m. yesterday, police said Manley Cannon, 40, of 67 R St. NE, was found in front of 11 R St. NE suffering several gunshot wounds. He died at Washington Hospital Center about 8 p.m. Homicide investigators late last night had not released any other details in the case.