A deputy constable in Houston who was shot four times Wednesday night after a suspect approached him from behind and opened fire in an apparent ambush is expected to survive after undergoing emergency surgery on Thursday morning.

Alden Clopton, an 11-year veteran of the force who is married and has children suffered wounds to the abdomen and had a bullet lodged near his heart, authorities said.

"It was completely unprovoked," a constable spokeswoman said. Both deputy constables were in uniform and had marked vehicles.

Asked if authorities believed the shooter was targeting law enforcement, Houston police spokesman Kese Smith told The Associated Press that both deputy constables were in uniform and had marked vehicles.

"I can't see how someone can mistake them for someone other than law enforcement," Smith said.

The suspect fired six shots, four of which hit Clopton, Walker said. Officials had said earlier that Clopton had a bullet lodged near his heart, plus abdominal wounds. The other shots hit the other deputy constable's car and the ground.

"It was virtually an ambush is what it was," Walker said, according to the Houston Chronicle.

Clopton's protective vest likely saved his life, and Walker said he faces a long recovery.

Authorities were questioning a male who showed up a nearby fire station after the shooting and matched the description of the suspected shooter, Smith said. The person had not been arrested or charged, he said, but authorities also were not currently looking for anyone else.

According to Smith, the shooting came after a female reserve deputy constable made a traffic stop and called Clopton to assist. The vehicle that was pulled over left and Clopton was standing outside the window of the female's vehicle when he was shot.

The female deputy constable got out and shot back, but it was unknown if she hit the fleeing suspect, Smith said. The person being questioned at the fire station did not have any injuries, Smith said, adding that he didn't think the shooting was related to the traffic stop.

Clopton is the second Harris County law officer to be shot from behind in an unprovoked attack in the past year. Texas prosecutors in August charged a 30-year-old man with capital murder in the killing of sheriff's Deputy Darren Goforth, who was gunned down while filling his patrol car with gas in what officials described as a "senseless and cowardly act."

The Associated Press contributed to this report.