A Mexico man was found guilty in Oxford County Superior Court Thursday of the 2022 murder of his 27-year-old stepson.

Thomas Tellier, 52, was convicted in a jury trial Thursday of the murder of Nicholas Trynor on Aug. 6, 2022.

The week-long trial culminated in a jury deliberation lasting about an hour before a guilty verdict was delivered to the courtroom.

Tellier was arrested and charged with murder on Aug. 6 after police responded to a call at the family home on Intervale Avenue in Mexico early that morning. Police found Trynor dead in a bedroom with two shotgun wounds to his chest and arms, which they later learned was from a Mossberg 500 pump-action 12-gauge.

According to court documents, Tellier told investigators a conflict between he and Trynor began earlier in the morning when Tellier’s 5-year-old autistic son hit Trynor. The 27-year-old slapped the boy and warned Tellier, “No one’s gonna hit me, you know, next time it happens … I’m gonna come after you.”

Tellier told police Trynor was generally “controlling and argumentative” and that his irritability from an earlier power outage turned to rage. Both men retreated to separate bedrooms to cool off, but Trynor later emerged still in a rage. Tellier said he grabbed his loaded shotgun out of fear for his family and tried warning Trynor off, but he would not leave the house.

When Trynor did not leave and continued to threaten, Tellier said, “It just happened,” and he pulled the trigger.

Jessica Tellier, Thomas’s wife and Trynor’s mother, told police that her son’s mental health issues with depression, anxiety, ADHD and anger issues caused him to lash out often. He would hit objects and make threats, but she never thought he was capable of harming her husband who, she felt, did not need to use a firearm.

An autopsy at the Office of Chief Medical Examiner determined Trynor died from massive internal bleeding after shotgun pellets perforated his chest, lungs, diaphragm and heart.

Tellier now faces a prison sentence of 25 years to life.