Arnold Police investigate the scene of a shooting of one of their own officers on Tuesday, Dec. 5, 2017, in the parking lot of the Arnold Police Station in Arnold, Mo. The officer was hospitalized with life-threatening injuries Tuesday after being shot inside a police SUV by a handcuffed burglary suspect he was taking to the police department for booking, authorities said. (J.B. Forbes/St. Louis Post-Dispatch via AP)

ARNOLD, Mo. - A suburban St. Louis police officer who was shot in the head by a handcuffed burglary suspect outside of the police station survived surgery and is in stable condition, authorities said.

Arnold police officer Ryan O'Connor, 44, was rushed to St. Anthony's Medical Center in St. Louis County on Tuesday after being shot by Chad Klahs, Jefferson County Sheriff's Captain Gary Higginbotham said. Klahs, 29, apparently fatally shot himself after wounding O'Connor, he said.

"Against all odds our officer has fought through the horrific incidents that occurred earlier today and remains in stable condition," the Arnold Police Department said late Tuesday on Facebook, noting that the 20-year law enforcement veteran will face a challenging recovery.

The shooting shook police in Arnold, a city of roughly 21,000 people about 15 miles (25 kilometres) south of St. Louis. Klahs had a long criminal record and Higgonbotham said he was well known to police.

Police were initially called after a gun was reported stolen from a home. Higginbotham said the suspect ran into the woods and officers heard shots fired, though it wasn't clear if shots were fired at them.

Police believe Klahs committed a second burglary after the home break-in, this time stealing a second gun from a vehicle at an auto body shop.

Officers arrested Klahs near a gas station and confiscated one gun, put him in handcuffs and into the back of a police SUV. But officers were apparently unaware of the second burglary or the presence of the second gun.

O'Connor drove Klahs to the police station to be booked. Officers inside watched on camera as the police SUV approached an area where suspects are taken out of police vehicles and brought inside.

When they didn't immediately come in, officers went outside and found that the SUV had crashed into a diesel fuel tank and both men were wounded inside the vehicle.

Higginbotham said Klahs apparently managed to get hold of the concealed gun despite being handcuffed, and shot the officer before turning the gun on himself. Both men were shot with a .40-calibre handgun.

Investigators are trying to determine why the second gun wasn't confiscated.

Arnold police Chief Robert Shockey said O'Connor has worked for the Arnold department for about three years and that he previously served in Ferguson and St. Louis County. O'Connor is a married father of four and is the son of Tom O'Connor, a former police chief in the St. Louis County town of Maryland Heights.

Klahs' fiancee, Amanda Cochran, told KTVI-TV that Klahs was impulsive but that the shooting came as a shock.

"He would be mad at himself for what he did. He would beat himself up so bad. I know right now he is up there crying," she said.

Missouri court records show Klahs had previous convictions for crimes including burglary, theft, assault, drug charges and receiving stolen property. He served some time in prison.

Missouri Gov. Eric Greitens visited O'Connor and his family at the hospital Wednesday, said Greitens' spokesman, Parker Briden.

News from © The Associated Press, 2017