TUCSON, Ariz. — A gunman dressed in camouflage shot at homes from a car Sunday and then fired at law enforcers who pursued him for an hour through Tucson, gravely injuring one, before he surrendered, authorities said.

No one in the homes was injured, but a 43-year-old Tucson police officer who had joined the force after a military career was on life support after being shot in the head, Police Chief Richard Miranda said.

Two Pima County sheriff's deputies were wounded with injuries not considered life-threatening, he said.

David Nicholas Delich, 25, was being held and interviewed by city police and sheriff's investigators Sunday night but had not been booked on any charges, said Rick Kastigar, criminal investigations chief for the sheriff's department.

It wasn't known whether he had a lawyer.

The gunman's motive for firing at the homes wasn't immediately clear, and police said he shot at officers from both inside and outside of his car at various points.

The chase began Sunday morning after residents reported shots fired by a man driving a red Ford Mustang. Deputy Eric Cervantez saw the suspect, who fired at him; Cervantez was shot in the shoulder as he returned fire, Kastigar said.

Cervantez chased the suspect despite being injured but lost sight of him. A second deputy spotted the car and picked up the chase, Kastigar said.

Later, the suspect shot Tucson police Officer Erik Hite apparently after making an abrupt U-turn, Miranda said. Hite, shot in the head, had been sitting in his car.

"I'm going to say it bluntly: Officer Hite was ambushed," the chief said.

Several miles away, the gunman shot and grazed the head of Deputy Tory Schwartz, authorities said. He eventually surrendered to deputies on a mountain road.

Miranda said several weapons and a lot of ammunition were found inside Delich's car, including an assault-style rifle. He said the sheriff's department has "had several contacts" with Delich over the years but gave no specifics.

Hite joined the department in 2004 after 21 years in the Air Force. He and his wife, Nohemy, have a daughter, Samantha, who will turn a year old next week. Hite also has a son serving in the military.

"I believe as police chief my ultimate responsibility is protection of my police officers, and when something like this happens I have a definite, sincere feeling of responsibility," Miranda said. "I have a sense of responsibility and sadness, and I feel absolutely terrible."