PENSACOLA (Florida) - TWO deputies killed by a soldier they were trying to arrest for beating his wife exchanged multiple rounds with the man who began shooting while on the ground after he was shocked with a stun gun, authorities said on Sunday, a day after the men were killed.

Interim Okaloosa County Sheriff Edward Spooner said that between 30 and 40 rounds were exchanged between 28-year-old Joshua Cartwright and the two deputies.

Investigators were working to determine the extent of Cartwright's military and militia weapons training, Mr Spooner said.

Cartwright was killed by deputies in a neighbouring county after he fled a shooting range parking lot near Crestview where he killed deputies Burt Lopez and Warren 'Skip' York. Cartwright's truck flipped on its side after the tires were punctured by spikes at a roadblock.

Investigators say Cartwright and deputies exchanged about 60 rounds in 30 to 40 seconds before he was shot and killed. They are awaiting autopsy results to determine whether either of the slain deputies struck Cartwright before they died.

In November, when authorities arrested Cartwright for domestic battery, they listed his employer as the US Army Reserves. But Mr Spooner said Cartwright was a member of a Florida National Guard unit based in Crestview. He said Cartwright also was interested in militia groups and weapons training.

Mr Spooner said he did not believe Cartwright was a war veteran, but that investigators are continuing to check his background.

Deputies went to arrest him at the gun range Saturday afternoon after taking a second domestic abuse report from his wife Elizabeth Marie Cartwright, 21, who was being treated for injuries at a local hospital.

Both deputies were wearing bulletproof vests but were shot in areas not protected by the vests, he said. The two men were pronounced dead after being airlifted to Sacred Heart Hospital in Pensacola, about 72 kilometres away.

The slain deputies, both 45, were retired from the US Air Force. Mr Lopez had five children and Mr York had a 10-year-old son. -- AP