US man killed two deputies after being stunned

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.

"When that Taser released after five seconds, he came up shooting," Interim Okaloosa County Sheriff Edward Spooner said.

"He went from just being disagreeable to using deadly force in a matter of seconds. It was a very aggressive move with a concealed weapon on his part."

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, 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.

"When he had his crash, the truck flipped upside down, nose first and he came out of the backside of the truck firing immediately and using the truck for cover," Spooner said.

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.