New details about New Hampshire triple murder emerge, including final messages wife sent to husband before she and her sons were killed


Kassandra Sweeney, 25, and her 4-year-old and 23-month-old sons were shot and killed in her Northfield home, allegedly by her husband’s then-16-year-old brother.

Kassandra Sweeney, 25, and her two sons, 4-year-old Benjamin and 23-month-old Mason, were shot and killed in their Northfield, New Hampshire, home on Aug. 3, 2022. GoFundMe

Prosecutors believe the last messages Kassandra Sweeney sent to her husband before she and her two sons were killed were Snapchat videos of their two young boys, followed by the text, “I hope they make you laugh,” according to The Boston Globe.

Less than 10 minutes after the messages were sent, Eric Sweeney, her husband’s then-16-year-old brother, allegedly gunned down the 25-year-old and her sons in her Northfield, New Hampshire, home, the Globe reported.

When they were killed the morning of Aug. 3, 2022, Benjamin Sweeney was only four years old, and Mason Sweeney was nearing two years of age. 

Later that month, Eric was arrested and charged as a juvenile with three counts of first-degree murder and one count of falsifying evidence in connection with the killings. Because of his age, his name was not released at that time. 

But early last month, Eric was indicted on the same charges as an adult even though he is still only 17 years old. As a result, prosecutors revealed his identity. 

What we learned about what happened that day 

According to court records, location data from Kassandra’s phone indicates that it began traveling away from her home at 56 Wethersfield Dr. down I-93 south just before 11 a.m., the Globe reported. About 20 minutes later, her husband, Sean Sweeney, received more messages from her Snapchat account, but they appear to have been from his brother. They reportedly said “Help. It’s Eric.” 

A little after 11:20 a.m., Sean called 911 and asked that an ambulance be sent to his home, the Globe reported. When asked what had happened, he said “I don’t know … my brother told me someone broke in and killed them all.”

Police found the three victims dead in the home around 11:30 a.m., the New Hampshire Attorney General’s Office said previously. Their deaths were soon ruled homicides, and the AG’s office revealed that they’d each died of a single gunshot wound. 

Kassandra Sweeney, 25, and her two sons, 4-year-old Benjamin and 23-month-old Mason, were shot and killed in their Northfield, New Hampshire, home on Aug. 3, 2022. – WCVB

Sean arrived at the scene after investigators, and GPS data from his truck indicated that he hadn’t been in Northfield since 6:30 a.m. that morning, the Globe reported. Eric, who lived with his brother and his family at the time, arrived at the scene soon after.

The teen told investigators he had been in the basement of the home when he heard yelling from a voice he described as being deep and male, followed by several “pops,” the Globe reported. He then waited for the noise upstairs to cease before leaving the basement, seeing the three victims on the floor in the kitchen, and taking Kassandra’s keys and phone, he reportedly told authorities.

At the time, Eric Sweeney told investigators he wasn’t sure if they were alive or dead, the Globe reported. 

What led investigators to suspect Eric

Sean had previously reported his brother to police in July 2022 citing safety concerns, the Globe reported. The teen had been making strange comments and hiding weapons around the home, Sean told police.

Police then met with Eric, and he told them he would change his behavior, the Globe reported. An officer told Sean to notify police again if he had any further safety concerns. 

After his wife and children were killed, Sean told authorities that Eric’s behavior had become so concerning that the couple had put a lock on their bedroom door, the Globe reported. They were also in the process of getting him removed from their home. 

Sean told authorities he owned two handguns, and that he kept them unloaded in a locked safe under his bed, the Globe reported. When investigators located the safe, they found it unlocked and missing one of the guns and a magazine. 

Authorities found the alleged murder weapon a little over a week after the shooting on the side of the road on I-93 south, the Globe reported. They allegedly found the key to the gun safe with the keys to the truck Eric had driven away from the scene and discovered gunshot residue on Eric’s hands and the steering wheel of the truck.

Prosecutors have yet to provide a motive for the murders, the Globe reported. One of Eric Sweeney’s lawyer’s declined to comment on the case to the newspaper on Monday.