Suspect in St. Louis Officer Ambush Killed in Shootout

— -- The suspect in an ambush-style shooting of a St. Louis police officer has been killed in a shootout with police, the St. Louis Police Department said early Monday.

Earlier in the night, a St. Louis police sergeant was shot twice in the head while sitting in his patrol car in what the police chief called a targeted ambush.

The officer is in critical condition but is expected to survive, officials say.

The suspect drove alongside the sergeant's marked vehicle and fired at him, Chief Sam Dotson of the St. Louis Police Department said.

The 46-year-old sergeant, who Dotson said has 20 years of service, was shot two times in the head and sustained injuries to the face. He was in critical but stable condition and was talking, and was expected to survive the police chief said.

"This officer was driving down the road and was ambushed by an individual who pointed a gun at him from inside of his car and shot out the police officer's window," he said.

“He was targeted because he was a police officer,” St. Louis Mayor Francis Slay said at a press conference. “He didn’t stop anybody. He didn’t point a gun at anybody."

The major said the husband and father of three was shot without provocation, adding that he was just doing his job.

Police say the suspect is believed to be responsible for string of recent crimes, and may have thought the officer was going to recognize him.

The sergeant was able to radio in for assistance, and when officers arrived, he was still sitting in his car with his gun in his holster, Dotson said. The sergeant was able to describe the vehicle as silver, the chief said

After launching what was called a “massive police operation” that included the FBI and the Bureau of Alcohol Tobacco and Firearms, officers located the suspect's vehicle in a parking garage.

They then spotted the individual, an African-American male born in 1997, riding in the passenger seat of a vehicle driven by a female. The suspect got out of the car and ran, leading police on foot through an alley and yard, and at one point fired into the windshield of an unmarked police car, injuring no one.

Several officers converged on the suspect and shot and killed him. Police say he was wanted for robberies, a carjacking and a possible homicide.

ABC News' Matt Foster contributed to this report.