BUTLER TWP — The suspected gunman who allegedly opened fire at another man at an apartment complex before shooting himself in the head Tuesday night remains hospitalized in Pittsburgh.

Michael L. Holt, 33, could face numerous charges, including attempted homicide and aggravated assault, Butler Township police said.

He is in serious condition, a spokeswoman at Allegheny General Hospital said this morning.

Police suspect a domestic dispute triggered the shooting about 10:20 p.m. at Whitestown Village.

Holt’s former live-in girlfriend was at the apartment to retrieve some of her belongings when one of her friends, a 39-year-old township man, drove there.

Township Police Chief John Hays said the older man went there “out of concern” for the woman. He did not know the relationship between the two.

Police have not yet identified the man and woman.

Holt left his apartment, armed with a 9 mm pistol, and fired at least six rounds while chasing the other man, who man got away uninjured.

Holt returned to his apartment. He locked the main door and went into the bathroom and locked that door, too.

Police got to the apartment, but Holt would not come out. Soon officers heard a gunshot. They kicked in the door and found Holt had apparently shot himself with a 7 mm rifle.

He was taken to Butler Memorial Hospital and later flown to AGH.

Police recovered the rifle and pistol. Hays said Holt owns the pistol and has a concealed carry permit for it.

“We still have some more to do before we complete the investigation,” Hays said this morning.

“Once we complete our investigation we’ll then discuss it with the district attorney to see what course of action we’ll take,” he said.