CONCORD, N.H. (AP) — A New Hampshire man accused of killing his sister-in-law and two young nephews when he was 16 pleaded guilty to second-degree murder charges Friday after prosecutors described a playful morning turned tragic.
Eric Sweeney, now 19, had been living with his older brother’s family in Northfield for three years when prosecutors say he fatally shot Kassandra Sweeney, 25, and her sons, 4-year-old Benjamin and 1-year-old Mason, in August 2022.
He was scheduled to go on trial on first-degree murder charges next month but instead pleaded guilty to the lesser charges in Merrimack County Superior Court, speaking only to briefly confirm his understanding of the proceedings. First-degree murder carries an automatic life sentence without parole. Second-degree murder is punishable by up to life in prison. Sweeney, whose lawyers had considered raising an insanity defense, will be sentenced on Oct. 3.
According to prosecutors, Sweeney’s older brother, Sean, and his wife were serving as the teen’s guardians when Sweeney’s “increasing behavioral issues” including lying and violating house rules began causing tensions in the home.
The couple called police twice: once when Sweeney took their truck without permission and again less than two weeks before the shootings to say he was making “strange statements,” Assistant Attorney General Bethany Durand said at Friday's hearing.
“The situation had deteriorated the the extent that Sean installed a lock on the door of the master bedroom in order to keep the defendant out of that room,” Durand said.
She described videos Kassandra Sweeney recorded and sent to her husband less than 10 minutes before they were killed: the toddler laughing as one of the family dogs nipped at the tail of his older brother's dinosaur costume, both boys looking out the window at a groundhog and saying “Hi, Dada” to the camera.
“The family was having a normal morning, with the boys playing and laughing with Kassandra while helping her to create video clips to send to their dad,” Durand said. “There was no indication of any unknown person, intruder or danger inside of their home.”
When he was taken into custody, Sweeney told police he had been in his room in the basement when he heard something break upstairs, a man with a deep voice yelling and multiple “pops,” according to court documents. He said he went upstairs and found his sister-in-law and nephews on the floor bleeding and then took Kassandra’s cellphone and keys and drove away. He then called his brother, who called police.
Investigators found Kassandra and Mason in the dining room and Benjamin in the kitchen, Durand said. All three had been shot once in the head, Benjamin through the hood of his dinosaur costume. The prosecutor said Sweeney used his brother's handgun, which was kept in a locked safe under the couple's bed.
Family members, some of whom wiped away tears during the hearing, declined to comment afterward, as did lawyers for both sides.
According to court documents, Sweeney left the couple a note when he took their truck in June 2022. “I do not belong in this family All I do is steal and lie and be irresponsible,” it read in part, closing with, “I love you big bro and sis bye.”
Savana Hammond, reacts as Eric Sweeney, accused of killing his sister-in-law and two young nephews when he was 16 pleaded guilty to second-degree murder charges on Friday, Aug. 15, 2025 at Merrimack County Superior Court in Concord, N.H. (Geoff Forester/ Concord Monitor via AP, Pool)
Eric Sweeney, accused of killing his sister-in-law and two young nephews when he was 16, enters court on Friday, Aug. 15, 2025 at Merrimack County Superior Court in Concord, N.H. (Geoff Forester/ Concord Monitor via AP, Pool)
Savana Hammond, reacts as Eric Sweeney, accused of killing his sister-in-law and two young nephews when he was 16 pleaded guilty to second-degree murder charges on Friday, Aug. 15, 2025 at Merrimack County Superior Court in Concord, N.H. (Geoff Forester/ Concord Monitor via AP, Pool)
