Donald Campbell wasn’t ashamed to be a mama’s boy, family members said. At 55 years old, he still lived with his 76-year-old mother. They would watch old movies or do crossword puzzles together. And he used to tell her that he wanted to die before she did, he loved her so much.

“Dear God, he got that wish,” his mother, Lillian Camp­bell-McKenzie, said Monday. “He died before me.”

On Saturday, Campbell was slain less than 100 yards from the Seat Pleasant home he and his mother shared for about 11 years.

Police arrested Archie Singleton, 43, of Upper Marlboro shortly after Campbell’s slaying, authorities said. Singleton was charged with second-degree murder and a handgun count in connection with Campbell’s death.

Authorities said that the two men knew each other and that Singleton worked at a window-tinting shop behind Campbell’s home.

Police answered a call about a shooting about 7 p.m. Saturday at Ultimate Window Tinting and Detailing off Central Avenue near the Addison Road Metro station. When they arrived, they found Campbell suffering from a gunshot wound. Officials pronounced him dead at the scene.

Singleton told police that he worked at the shop and during the interview, they found he had a handgun, authorities said.

“He was taken for additional questioning, during which he admitted his involvement in the shooting,” according to a statement from Prince George’s police about the case.

Police were still investigating the motive behind Campbell’s death as of Monday, Lt. William Alexander, a Prince George’s police spokesman, said.

Campbell’s family members said they were baffled by the circumstances of the shooting, especially since Saturday started off like any other day.

That afternoon, his sister Angela Campbell said, the two were outside, hanging out in back of the Campbells’ home, enjoying the warm weather, when he called out to her and asked for a cigarette. She replied that she didn’t want to go inside to get one, so he left.

That was 30 minutes before he was killed, Angela Campbell, 52, said.

“ ‘Tell Mama I love her, and I’ll be home in a minute,’ ” she said her brother told her. “That was his last words to me.”

Angela Campbell said her brother was a Dallas Cowboys fan and had the quirky habit of playing Christmas music in July. He had a son and a daughter, both in their early 20s.

Campbell-McKenzie remembered her son’s volunteering with her as she did missionary work, serving food at homeless shelters and delivering food baskets. She said she would miss his reassuring presence.

“He would always say, ‘We’re going to be all right, everything is going to be fine,’ ” Campbell-McKenzie said. “He always wanted me to look ahead and not be sad.”