PARIS — A Mexico man is currently on trial in Oxford County Superior Court for the 2022 death of his adult stepson.

Thomas Tellier, 52, is accused of fatally shooting his stepson Nicholas Trynor, 27, at their Harlow Hill Road home in Mexico on Aug. 6, 2022.

Tellier called 911 around 11:45 a.m. on Aug. 6, 2022, police said, reporting he and Trynor had gotten into a heated argument after Trynor slapped Tellier’s 5-year-old autistic son and threatened him with violence.

After retreating into separate bedrooms to cool off, Tellier claimed that later that morning, Trynor emerged still in a rage. Allegedly fearing for his and his wife’s and son’s lives, Tellier grabbed his Mossberg 500 12-gauge shotgun and fired at Trynor twice, hitting him in the chest and arms.

Prosecutors argued at Tellier’s October 2022 arraignment that Tellier intentionally shot Trynor in an unnecessary escalation during a family dispute. The confrontation could have been diffused without deadly force, prosecutors said.

Tellier’s defense attorney George Hess argued at the arraignment that Tellier acted to protect his family from what seemed to be a legitimate threat to their lives. Hess described Tellier as a family man who believed he had no choice other than to react with deadly force.

The trial, which began on Wednesday, is expected to continue into the following week.