A 19-year-old man has pleaded guilty to killing his sister-in-law and two young nephews in a case that shocked the New Hampshire community.
Eric Sweeney accepted a plea deal Friday, admitting guilt to three counts of second-degree murder and one count of falsifying physical evidence for the deaths of Kassandra Sweeney, 25, and her sons Benjamin, 4, and Mason, 1. According to Daily Mail Online, Sweeney fatally shot his victims execution-style with bullets to the head using his older brother's gun at their Northfield home.
The teenager had originally faced first-degree murder charges and was scheduled for trial in September. Prosecutors cited a chilling note Sweeney left behind two months before the killings as evidence of his deteriorating mental state and growing family conflicts.
Warning Signs Preceded Fatal Shootings
Sweeney had penned a disturbing letter in June 2022, just two months before the August killings, when he took the family truck without permission. The note read in part, "I do not belong in this family. All I do is steal and lie and be irresponsible," ending with "I love you big bro and sis bye."
Assistant Attorney General Bethany Durand told Merrimack County Superior Court that this message served as an early indication of emotional instability. Kassandra and her husband Sean Sweeney had been acting as Eric's guardians and struggled to manage his behavioral issues, which included lying, stealing, and breaking household rules.
Police had been called to the home twice before the murders. The first incident occurred after the stolen truck episode, and the second came less than two weeks before the fatal shootings when the couple reported Sweeney was making "strange statements."
Family Dynamics Deteriorated Before Tragedy
The situation in the household had become so tense that Sean installed a lock on the master bedroom door to keep Sweeney out of that room. Prosecutors described a family environment where the guardians were struggling to control an increasingly problematic teenager whose behavior was escalating.
On the morning of the killings, Kassandra had been recording video clips of the boys playing and sending them to her husband at work. In one clip, the toddler giggles as a family dog plays with the tail of his brother's dinosaur costume, while in another, both children wave at a groundhog outside 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."
Investigation Revealed Fabricated Story
Sweeney initially provided a false account to police, claiming he had been in his basement bedroom when he heard something break upstairs. He told investigators he heard a man yelling and several loud "pops," then went upstairs to discover the victims on the floor before taking Kassandra's phone and car keys and leaving the house.
The teenager claimed he then called his brother, who contacted law enforcement. However, investigators determined this story was fabricated as part of an attempt to cover up his crimes.
Kassandra and Mason were found in the dining room, while Benjamin was discovered in the kitchen, each having been shot once in the head. Prosecutors revealed that Sweeney used his brother's handgun, which had been kept in a locked safe under the couple's bed.
Sentencing Awaits Triple Murderer
Family members sat quietly during Friday's emotional hearing, with some seen wiping away tears as the details of the case were presented. Neither family members nor attorneys for either side provided statements after the court session concluded.
Sweeney faces a potential sentence of 35 years to life in prison for each second-degree murder charge when he appears for sentencing on October 3. The plea deal allowed him to avoid the possibility of life without parole that could have resulted from first-degree murder convictions.
The case has highlighted the challenges families face when dealing with troubled teenagers and the tragic consequences that can result when behavioral problems escalate unchecked. The young victims' deaths have left a community mourning the loss of innocent lives cut short by family violence.
