Trevor Mercier, the Libby man convicted Aug. 10 of deliberate homicide in the October 2016 death of Sheena Devine, was sentenced Tuesday to life in prison without the possibility of parole.

“Sir, you have been convicted of the most serious crime that we have in Montana, and you have been convicted of doing it in the most violent way it can be done,” Judge Matt Cuffe told Mercier before handing down the sentence in Lincoln County District Court.

Devine’s body was found in her home by her two young daughters on Oct. 6, 2016. Investigators arrested Mercier in his home the following day after identifying him as a prime suspect in Devine’s death. Mercier and Devine had been in a relationship that had ended before the incident. In court it came out that the night of Devine’s death, she and Mercier had fought after Mercier threw a rock at her car, smashing its windshield.

“Anyone who would react in that way to a breakup is a danger to society,” Cuffe said to Mercier before sentencing him.

Mercier’s defense acknowledged at trial that he had caused Devine’s death but that it was a case of negligent homicide, because he did not intend to kill her. The defense said while fighting Mercier put Devine into a “sleeper hold,” rendering her unconscious. Afterward, the defense said, Mercier took her inside her house, placed her on the floor, checked to make sure she was still breathing and then left the house.

Prosecutors argued that Mercier had strangled Devine long after the 10 to 15 seconds a “sleeper hold” takes to render someone unconscious, and that he had beaten her so badly that she had hemorrhages all around her head and sternum.

When asked by Cuffe if he wished to make a statement before his sentencing, Mercier conferred with his attorney Backus before saying “No, your honor.”

Cuffe also gave Mercier a concurrent 10-year sentence for tampering with evidence.