Charges are pending against the man accused of shooting a Griffin police lieutenant in the head, police said Thursday.

The shooting suspect remained in critical condition, but the lieutenant was released from the hospital.

“He is at home,” Griffin police spokesman Capt. Dwayne Jones told the Atlanta Journal-Constitution. “He is recovering.”

Steven Walker, 42, had a semi-automatic weapon and at least 12 rounds of ammunition fired at two Griffin police officers Wednesday night, injuring Lt. Curtis Keys, a 12-year veteran with the department, according to police.

The lieutenant was coming to the aid of a fellow officer when he was struck, Jones said.

One of the first officers to respond, Officer Colt Tolen, fired back at Walker, critically injuring the man, police said. Tolen was not injured.

Keys was taken to Grady Memorial Hospital where he was treated for non-life-threatening injuries and released this morning, Jones said.

Walker remained in critical condition Thursday afternoon at Atlanta Medical Center, where he underwent surgery overnight, according to police. Walker will be charged with two counts of aggravated assault against an officer, and additional charges are pending, Jones said Thursday afternoon.

The incident began around 10:15 p.m. when Officer Tolen responded to the 400 block of Circus Street on a report of man wearing all black and waving a gun around in the front yard, Jones said.

Tolen arrived and found Walker, who started running, Jones said. Walker fired shots at the officer, who returned fire, Jones said.

The officer was not injured, but he lost sight of the suspect, Jones said. Keys, arriving to assist the officer, was still in his patrol car when Walker allegedly fired a shot through the windshield, striking the lieutenant in the head, Jones said. At that point the first officer fired back, hitting the suspect several times, according to police.

The injured lieutenant was conscious while being flown to Grady , Jones said.

In addition to having a semi-automatic weapon, Walker had a dozen rounds of ammunition in his back pocket and was wearing a shoulder holster, Jones said. No one else was injured.

The Georgia Bureau of Investigation was assisting with the investigation into the incident late Wednesday, Jones said. The officer who fired at the suspect was placed on administrative leave, which is protocol for officer-involved shootings, according to police.

— Staff reporter Marcus K. Garner contributed to this article.