FRANKLIN — A suicidal man made an improvised sniper's "perch" in an upstairs bedroom so he could fatally shoot a state trooper who volunteered to investigate a domestic-abuse report because he had previous contact with the gunman, the state police commissioner said.

Michael J. Smith, 44, arranged folded towels and blankets on a corner table to steady a scope-equipped .30-30 hunting rifle that police believe he used to shoot Trooper Paul Richey in the neck, above his bulletproof vest, late Wednesday morning, Col. Frank Pawlowski said.

"This was a premeditated event. This was an ambush," Pawlowski said. Smith positioned himself so he could fire his weapon from a vantage point some distance back from an open window that let him see the approaching troopers without them seeing him, Pawlowski said.

Police believe Smith used the same weapon to kill his 53-year-old wife, Nancy Frey-Smith, and himself. Her body was found in a bedroom chair and his, still clutching the gun, was near the foot of the bed, Pawlowski said. Pawlowski said it's likely Smith shot his wife before shooting Richey, because there's no sign she tried to stop the shooting or warn the troopers. Autopsy and ballistics results are needed to confirm the rifle was the weapon used in all three deaths.

The rifle is the same one Smith used to threaten his wife 13 years ago, Pawlowski said. Police want to determine how the weapon was returned to Smith because it had been seized under a protection-from-abuse order issued in 1997.

"That will be part of our investigation," Pawlowski said. "I'm at a loss right now, to be honest with you. But I'm not happy about it."

Pawlowski said Smith had mental health issues and was known to have neighborhood disputes, though none were violent or otherwise sent up "red flags." Pawlowski said Frey-Smith had done a "pretty good job of controlling her husband and calming him down" in the past, and that the family chose to deal with his unpredictable ways by themselves.

On Wednesday, Smith's 44th birthday, Frey-Smith's sister called police to express concern for her sister's safety. Richey, 40, of Franklin, volunteered to accompany another trooper on the call because he knew Smith — likely because Richey grew up nearby and had encountered Smith during other disturbance calls at the house.

Frey-Smith's sister said the woman told her in a phone call that she wasn't going to work because Smith was in "one of his moods," according to a police search warrant affidavit.

The sister then spoke to Frey-Smith's boss, who said she reported having been assaulted by her husband. The sister called back and spoke to the couple, saying she was coming over to see her sister.

The sister said Michael Smith told her "she shouldn't bother coming and that she had 'just signed Nancy's death warrant,"' the affidavit said. She then called police.