A New Hampshire teenager who killed his sister-in-law and two young nephews when he was 16 years old faced sentencing on Friday, October 3, 2025. Eric Sweeney, now 19, pleaded guilty in August to three counts of second-degree murder for the deaths of Kassandra Sweeney, 25, and her sons Benjamin, 4, and Mason, 23 months old.
According to Court TV, the murders happened on August 3, 2022, at the family’s home on Wethersfield Drive in Northfield, New Hampshire. Sweeney was living with his older brother Sean and his family at the time because Sean and Kassandra were his legal guardians.
On that morning, Kassandra had been recording videos of her children playing and sent them to her husband. Just four minutes after the last video was sent, all three victims were shot once in the head with a Taurus .40 caliber handgun that belonged to Sean.
After the killings, Sweeney took Kassandra’s phone and Ford F-150 truck and left the home without seeking help. He called his brother 17 minutes later, claiming someone had broken into the house. During a police interview, Sweeney said he was in the basement when he heard a “deep male voice” and gunshots before finding the victims. But investigators found no signs of forced entry or a home invasion at the house.
What the investigation found
Prosecutors said that Benjamin was wearing a dinosaur costume when he was killed, shot through the hood. The autopsy showed that both Kassandra and Benjamin had burns on their skin from gunpowder. This meant they were shot from a distance of 6 to 30 inches away. Mason’s body was found with his mother in the dining room, while Benjamin was found in the kitchen.
'THEY WERE INNOCENT': Prosecutors want up to 97 years in prison for New Hampshire teen Eric Sweeney who shot dead his sister-in-law and her 2 young sons in 2022.
— Graham Hodson
Prosecutors say the murders deserve consecutive sentences. pic.twitter.com/YzljNRMIDk(@2grahamhodson) October 3, 2025
Sweeney threw away the murder weapon on a highway. Records show that just 12 days before the murders, Sean Sweeney had called police because he was worried about Eric’s strange behavior. An officer talked with Eric at the time, and he promised to change his behavior. Court documents showed that Eric’s growing behavioral problems, including lying and breaking house rules, had been causing problems in the home.
Defense lawyers said that Sweeney went through terrible trauma as a child, including a mother who took him through drug dens and abusive situations. This case is similar to other high-profile murder trials involving young defendants that have gotten public attention in recent years. They asked for a sentence of 40 years to life, to be served at the same time, which could allow him to leave prison at age 56.
Prosecutors wanted back-to-back sentences adding up to 115 years to life in prison without parole. Assistant Attorney General Bethany Durand said that the children “did absolutely nothing wrong, they were innocent and utterly blameless for what the defendant did.” Authorities say that crimes against children deserve the toughest penalties available under the law.
No reason for the killings has been given. As part of his plea deal, Sweeney cannot make money from the case and must have no contact with family members except his mother.
