LANCASTER — A 51-year-old Pittsburg man was sentenced Wednesday to 33 1/2 years to life in prison after he pleaded guilty to gunning down three people in a November 2010 shotgun ambush that left a 21-year-old West Stewartstown man dead.

If Kenneth Arsenault completes his minimum prison term, he'll be 84.

“It's a significant sentence,” Senior Assistant New Hampshire Attorney General Jeffery Strelzin said.

Arsenault was convicted for killing Justin Flanders who, according to the New Hampshire Chief Medical Examiner's Office, died of a 20-gauge shotgun wound to the chest and of severe burns. Police found his body in a burned-out vehicle on Arsenault's Pittsburg property on Nov. 2, 2010, the day of the shootings.

Strelzin said Arsenault “had issues with” Tanya Ranclose, 30, of Colebrook, including claiming that Ranclose had been pressuring Arsenault's girlfriend to provide her with drugs.

Arsenault lured Ranclose to his home, and was hiding when she, Flanders and Jessie Parker, then 25, of Littleton, arrived. Arsenault opened fire on the three, according to Strelzin.

Strelzin said it was “never definitely determined” how the vehicle fire started, but passing motorists found Ranclose and Parker. Neither victim was in court Wednesday.

Arsenault pleaded guilty in Coos County Superior Court to one count of second-degree murder and two counts of second-degree assault.

Judge Peter H. Bornstein sentenced Arsenault to 30 years to life on the murder charge and a consecutive sentence of 3 1/2 to seven years on one assault charge and a concurrent 3 1/2- to seven-year term for a second assault conviction.

Strelzin said Flanders' family, including his parents, Jeff and Alberta Flanders, told him they were satisfied with the length of Arsenault's prison term.

Arsenault was represented by Caroline Smith of the New Hampshire Public Defender Program in Keene.