SOUTHFIELD, Mich. -- A man killed Sunday in a shootout at a suburban Detroit police headquarters first tried to shoot an officer behind bulletproof glass before officers exchanged gunfire with him, police said.

One police officer was wounded in the shootout in Southfield, a city of about 73,000 north of Detroit. The injured officer was in stable condition Sunday night with a single gunshot wound in the shoulder and expected to live.

Police Chief Eric Hawkins said investigators were trying to figure out why the gunman carried out the attack. The 64-year-old man had no known grievance with police.

"He didn't say anything," Hawkins said at a news conference. "The officers said he had a blank stare on his face."

Investigators didn't immediately know if the man had a criminal record and were in the process of contacting his family, the chief said. The dead man's name was not immediately released, but police said he lived in Southfield.

According to Lt. Nick Loussia, the confrontation began when the man entered the lobby of police headquarters and a desk officer asked if he could help him. The man then pulled out a handgun and pointed it at the officer, who was behind protective glass. The man pulled the trigger, but the gun did not go off, Loussia said.

The desk officer drew his handgun and told the suspect to drop his weapon, Loussia said. Other officers came to help and again ordered the man to drop his gun, Loussia said.

Instead, the man pointed his gun at the officers, Loussia said.

"The officers then exchanged shots with the subject. The first responding officer was shot once in the shoulder, the subject was shot several times," he said.

Hawkins said the wounded officer is 50 years old and a 25-year veteran of the force.

"He is conscious, alert and in good spirits," said the chief.

Hawkins praised his officers' actions in the shooting.

"My officers performed courageously under difficult conditions," Hawkins said. "We regret the loss of life. In this situation, the use of force was unavoidable."