Juvenile charged with first-degree murder in Northfield triple homicide

Aug. 11—A minor has been arrested and charged in the death of Kassandra Sweeney and her two young sons in their Northfield home last week, authorities announced on Thursday.

A statement issued by Attorney General John Formella said the juvenile has been charged with three counts of first-degree murder in the Aug. 3 deaths of Sweeney, 25, and her two children: Benjamin, 4, and Mason, 1.

Each died from single gunshots.

The announcement ends a week of speculation and confusion following the murders, when authorities announced that they had identified all parties and that the public was not in danger, but no arrests had been made.

The Thursday afternoon announcement did not give the time of the arrest.

Under New Hampshire law, juvenile court proceedings are conducted in sealed courtrooms, and records remain sealed. But state law includes a procedure to certify juveniles to stand trial as adults in open court.

A judge weighs factors such as a child's age, the severity of the crime, premeditation and community protection to make the decision. Lawyers said the process takes about four to six months, after which they can publicly discuss the case.

At a news conference later Thursday, Senior Assistant Attorney General Geoffrey Ward would not comment on whether the state would petition to certify the juvenile as an adult.

Police were called to the Sweeney home at 56 Wethersfield Drive at 11:33 a.m. Aug. 3 to find the three victims.

According to previous media accounts, the Sweeneys purchased their home in March 2021. On his Facebook page, the father, Sean, said he is a trucker.

He last posted on his Facebook page on Sunday, saying he was devastated, thanking people who supported him and praising Kassandra as the "most amazing, caring, sweetest all around good person that anyone could ever meet."

His family, he said, "will be forever loved and missed and forever in my heart."

mhayward@unionleader.com