NEW ORLEANS (AP) — A Louisiana trooper died Monday, a day after an apparently stranded motorist shot him in the head and then stood over him to tell him he was going to die soon, state police said.

Authorities plan to charge the accused shooter with first-degree murder after the death of Senior Trooper Steven Vincent, 43. Vincent had been trying to help a man whose pickup truck was stuck sideways in a ditch, Col. Mike Edmonson said.

“This loss exacts an enormous emotional toll on the state police family, but we will do what is necessary and proper to honor Steve and support those who knew and loved him,” Edmonson said in a statement Monday morning.

Edmonson said Kevin Daigle, 54, of Lake Charles, was under arrest at a hospital where he was taken after other motorists saw the fallen policeman and wrestled Daigle to the ground.

Police video showed Vincent, a 13-year state police veteran in southwest Louisiana and member of a law enforcement family, very professionally trying to talk a man out of the vehicle stuck sideways in a ditch, Edmonson said during a news conference Sunday.

He said the truck door opened and Daigle came out with the shotgun.

“That shotgun wasn’t to do anything else but hurt someone. Kill someone,” Edmonson said.

He said the tape shows the shotgun blast. “I saw my trooper go backwards and back toward his unit, where he was going to try to get some help out there,” Edmonson said.

After the shooting, he said, Daigle wandered into the road and over to Vincent, asking if he was alive.

“You could hear him breathing, telling him, ‘You’re lucky. You’re lucky — you’re going to die soon.’ That’s the words that came out of his mouth,” Edmonson said.

He said two or three drivers stopped immediately, one of them spinning around on the two-lane highway.

That driver wrestled the shotgun away from Daigle, and, with the others, got him to the ground, and snapped Vincent’s handcuffs on his wrists, Edmonson said. As far as he knew, he said, the good Samaritans were unhurt.

Edmonson said Daigle had “numerous DWIs” and other arrests that he wouldn’t discuss because he didn’t know whether they resulted in convictions.

Sgt. James Anderson, southwest Louisiana spokesman for state police, said Daigle was hospitalized for some scrapes and other injuries he sustained while the other motorists subdued him.

Both Daigle and the trooper who was shot are white, he said.

Edmonson said Vincent leaves behind a wife, Katherine, and a 9-year-old son, Ethan. Edmonson said one of Vincent’s brothers is also a state trooper, while another is police chief in the nearby town of Iowa (pronounced EYE-oh-way).

“His family lives and breathes law enforcement,” Edmonson said.