Emanuel Burl Patterson, 23, killed four men and wounded a fifth Tuesday in a rage apparently sparked by taunts and an argument over a CD player.
"It happened in just moments," said Police Chief Compton Owens, describing the carnage as "a scene that words cannot describe."
The violence erupted at 6:30 a.m. at Labor Ready Inc., where as many as 15 people had gathered waiting for work. Patterson had often been at the agency.
Huntsville police spokesman Wendell Johnson said while waiting, two groups of men began arguing over a CD player. Patterson then made a remark about settling the argument, pulled out a gun and opened fire, authorities said.
Eight hours later, Patterson surrendered after police surrounded his apartment building, evacuating everyone nearby. Authorities allege that Patterson, who was apparently holed up alone, shot at officers during the standoff, though no one was hit.
"People who know him say he is a very unstable individual," Johnson said, without elaborating.
Madison County District Attorney Tim Morgan said capital murder charges were likely. Conviction could carry the death penalty, or life in prison.
Morgan added that Patterson previously had only minor run-ins with the law.
According to witnesses, a seemingly petty argument quickly escalated at the agency. Michael Tucker Jr., whose father was in the Labor Ready office when the gunfire erupted, said his father told him the argument "was all over something about CDs and $20."
"There was some guys picking at (the gunman) and pushing him, laughing at him," Tucker said. "They pushed him into a corner."
Tucker said the suspect "stepped out, stepped back in and immediately started shooting."
"He shot the first guy in the head and then shot another guy and tried to shoot a woman," Tucker said. "He just started pointing the gun all over."
Police Lt. Vince Dauro said he found two of the dead on the floor of an entryway inside the building. Two other victims were on the ground outside, one dead and the other with fatal wounds who died at a hospital, Dauro said.
Patricia Johnson, 38, told The Huntsville Times the gunman turned his weapon on her and pulled the trigger, but it did not fire. She ran into a closet where three or four people already were hiding.
Chester Horton said Patterson had moved in early last week at the single-story brick apartment building where the siege ended. Horton, who lives in the building, said he was awakened about 7 a.m. by a noise like a gunshot or slamming door. He and his two sons were able to get out safely as police swarmed the area.
Horton described Patterson as "a strange guy" who seemed aloof and quiet.
According to police and witnesses, the gunman shot to death Billy Knox Jr., 22, and his father, Billy Knox Sr., 61, both of Huntsville, inside the building, then turned the gun on others at random.
Police said Benjamin Ferguson, 47, of Huntsville, was killed as he ran down the front steps, and David Seiler, 46, from Tennessee, was shot on the front steps and died at a hospital. A fifth man, Royce Henderson, 46, of Huntsville, was shot in the leg and survived.
By Jay Reeves