A former Army staff sergeant shot his son in the chest during a fight, then chased him down three flights of stairs to the parking lot of their Gaithersburg apartment complex, according to prosecutors.

There, 23-year-old Matthew E. Price collapsed and his father, Wayne M. Price, made no attempt to provide first aid or revive him, despite having received paramedic training from the military, Montgomery County prosecutor Jeffrey Wennar said in court Monday.

But Wayne Price’s attorney says his client followed his son downstairs to see if he needed help. Wayne Price called 911 and tried to alert a police officer who lived in their building, defense attorney Steven Kupferberg said after Monday’s bond hearing.

Price, 55, is charged with first-degree murder in his son’s death. District Court Judge Eugene Wolfe ordered him to remain in custody without bond.

The two had apparently had a fight over whether Matthew Price would continue living at the apartment on the 7900 block of Spiceberry Circle,  Kupferberg said. The shooting happened at about 8:45 p.m. Saturday.

Wayne Price was a health care specialist in the U.S. Army, said Ray Gall, spokesman for the Army Human Resources Command. He enlisted in 1988, left the Army at some point, then reenlisted in the Army Reserves in 2003, Gall said. He retired in 2007.

Kupferberg said Wayne Price had been working as a security guard since he retired from the military, but would not say where he worked.

The killing was the second homicide of the weekend in Montgomery County. Earlier Saturday, 44-year-old Hector Granados allegedly stabbed his estranged wife to death. Ana Ayala was found wounded in her vehicle on the 8600 block of Garland Avenue in Silver Spring and died at a hospital.

Granados is charged with first-degree murder and is being held without bond.

Including the weekend slayings, Montgomery has recorded five homicides in 2012, according to police data. In four of those, the victims were killed by relatives or romantic partners.