17-Year-Old Accused of Fatally Shooting His Sister-in-Law and Her 2 Young Children, 1 and 4

Eric Sweeney, 17, has been indicted by a New Hampshire grand jury on three counts of first-degree murder

More than a year after a mother and her two young children were shot dead in their Northfield, N.H., home, the woman’s 17-year-old brother-in-law has been indicted on three counts of first-degree murder.

A grand jury indicted Eric Sweeney, 17, on three counts of first-degree murder “for purposely causing the deaths" of his sister-in-law, Kassandra Sweeney, 25, and his nephews, Benjamin Sweeney, 4, and Mason Sweeney, 23 months, the attorney general of New Hampshire alleged in a press release yesterday.

Related: N.H. Mom and 2 Children, 4 and 1, Are Found Fatally Shot, Police Say There's 'No Threat to the General Public'

The teenager has also been indicted on one count of falsifying physical evidence. Investigators believe that “knowing that an investigation was about to be instituted,” Eric Sweeney tried to “alter, destroy, conceal, or remove a Taurus .40 caliber handgun, with the purpose of impairing its availability in said investigation,” according to the attorney general’s office.

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Eric Sweeney's brother, Sean Sweeney, was not killed with his family, according to a former campaign on GoFundMe, which raised $53,300 for the triple funeral.

Alizabeth Dawson, who identified herself as Kassandra’s cousin, wrote on the page that Kassandra was "one of the most genuine and beautiful people you could ever meet."

Eric Sweeney is currently behind bars and awaiting arraignment. It is unclear if he's retained an attorney to speak on his behalf.

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