For 24 years, Alva Porter has fielded countless 911 calls for shootings in her job as a Baltimore police dispatcher. 

Porter was not working Saturday night, when dispatchers took a call for a fatal shooting that turned out to be her 41-year-old son, David. He had been shot to death at a Northeast Baltimore barber shop.

"We kind of try to detach ourselves from it," she said of her work. "We do our best to get as many police to different scenes and locations as possible."

"It's different when it hits home," she said. "It touches you, and it changes you."

Porter said her son was getting his hair cut as he prepared to go to a reunion on the city's east side. She found out about his shooting after his friend, who had been trying to reach David without luck, saw the police tape and brought her there.

According to police, a surveillance camera captured the gunman entering the shop in the 4400 block of Frankford Ave. The others in the shop barely react as the shots are fired, police say. A possible motive was not provided.

David Porter served two decades in prison after being convicted in a fatal shooting in 1994, when he was 23 years old.

Alva Porter said he had been out for about three years, and court records show he had not been re-arrested. She said he had two children, and was getting ready to open a used car lot. 

"Everybody was helping him, because they loved him," she said. "If you knew my child, you would know that once you made him his friend, you were his friend for life. If you were his enemy, he was going to make you his friend."

Police Commissioner Anthony W. Batts did not respond to messages seeking comment. 

Anyone with information about David Porter's killing was asked to call 410-396-2100.