WATERTOWN, N.Y. (AP) — A former Army sergeant on trial for killing his wife and a state trooper in northern New York wasn't responsible for his actions due to his mental state, his defense lawyer told a jury Tuesday.

Justin Walters is accused of fatally shooting his wife in the driveway of their home in rural Jefferson County in July 2017. Authorities say he then gunned down 36-year-old Joel Davis moments after the trooper arrived to respond to reports of shots fired on the couple's property in the town of Theresa.

WWNY television reports that defense lawyer Ed Narrow told jurors during opening statements that the facts in the case are not in dispute. But Narrow said Walters' mental state when the shooting happened is in question.

Narrow said Walters, "was not responsible for his actions due to mental disease or defect."

Senior Assistant District Attorney Nicole Kyle told jurors that while the defense would argue that Walters was under the influence of post-traumatic stress disorder and alcohol, "the evidence will show he knew exactly what he was doing."

Walters faces 55 counts, including two for murder.

Walters was a staff sergeant with the 10th Mountain Division based at nearby Fort Drum. He served two tours in Afghanistan.

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