Prosecutors grilled Seth Fontenot in a contentious cross examination Tuesday in his first-degree murder trial in the shooting death of 15-year-old Austin Rivault, characterizing the incident as an “ambush.”

Fontenot maintains he never intended to hurt anyone, that he wanted only to scare suspected burglars by firing at their truck when he killed Rivault and wounded two other 15-year-olds in the Feb. 10, 2013, shooting in front of his home.

“You are either a lucky shot and hit three out of three, or you knew exactly where you were shooting,” Assistant District Attorney J.N. Prather said during a heated two-hour cross examination of Fontenot.

Tuesday was the final day of testimony in a trial that began last week.

Closing arguments are scheduled Wednesday morning, and the jury is expected to be deliberating the case by the afternoon.

Fontenot was on the witness stand Monday and Tuesday. He testified he had seen two people trying to break into his Chevrolet Avalanche about 1:45 a.m., ran outside with his 9mm Beretta and fired three shots, first aiming at a tire, then at the tailgate.

Each of the three bullets hit one of the teenagers in the cab of the truck.

Prather painted the picture of a young man who was angry and frustrated about a series of prior burglaries and shot to kill.

“You had enough, right?,” Prather said. “And you took it out on those three kids.”

The prosecutor, who denies the teenagers were up to no good, also showed jurors text messages from Fontenot a month earlier in which he wrote about buying a pistol and shooting anyone he caught breaking into his truck.

“So you are sitting there talking about shooting people and buying a gun, and you in fact went out and got a gun and shot somebody,” Prather said.

Fontenot testified Monday that he and his stepfather purchased the gun less than two months earlier at Lafayette Shooters after a string of burglaries and attempted burglaries of his truck and his mom’s vehicle at their home on Green Meadow Road.

Fontenot, who was 18 at the time, said he never owned a pistol before he bought the Beretta and had fired his new gun only once before the February incident.

His defense attorney, Thomas Guilbeau, argues his client was so inexperienced with a handgun that he couldn’t have fired three accurate shots if had wanted to, especially when shooting at a moving truck with tinted windows at night.

“You’re trying to say this is random?” Prather asked Fontenot.

“Yes,” he replied.

In recounting the details of the shooting on the witness stand Monday, Fontenot said he heard what sounded like someone trying to break into his vehicle, jumped out of bed, grabbed the pistol off his desk and then raced to the dining room, where he looked out the window and saw two figures in his yard.

Fontenot said he was wearing only boxer shorts and red Converse sneakers when he ran outside, saw a truck’s headlights come on, and yelled “freeze” and “stop” before firing three shots in rapid succession.

One bullet struck Rivault in the head, killing him.

The two other shots wounded Cole Kelley and William Bellamy.

Both of them testified last week they were dropping Rivault off at his home a few doors down from Fontenot’s house and had no idea why someone was firing at them.

On Tuesday, Prather picked apart inconsistencies between Fontenot’s testimony and the statement he gave to police just hours after the shooting, at one point slamming a copy of the transcribed police statement on the witness stand in front of Fontenot.

“You expect me to be a detective myself and tell you every single detail of that night?” Fontenot countered. “I didn’t know what happened.”

The trial resumes at 10 a.m. on Wednesday.

Fontenot faces life in prison if convicted on the murder charge.