The body of Kassandra Sweeney, 25, was discovered alongside her four-year-old son Benjamin and one-year-old son Mason at their house in Northfield on 3 August
The child, who will be tried under the juvenile system, has been charged with three counts of first-degree murder and one count of falsifying physical evidence in connection to the three deaths.
The body of Kassandra Sweeney, 25, was discovered alongside her four-year-old son Benjamin and one-year-old son Mason at their house in Northfield on 3 August by police responding to a 911 call.
Autopsy reports determined each died of a single gunshot wound.
Police have not revealed the name and age of the accused due to legal restrictions on sharing information on children charged with crimes.
New Hampshire’s senior assistant attorney general Geoffrey Ward said: “We don’t anticipate any other charges coming.
“Like I said, we believe – and we believed last week – that we had identified all individuals involved.”
He did not reveal whether the suspect was connected or known to the family or what evidence has been found.
The three deaths which were ruled homicides sparked rumours and fear among people in Northfield.
In a statement to The Independent on Tuesday morning, New Hampshire attorney general John Formella said there is no threat to the general public and they have identified all the parties involved.
A funeral for Kassandra Sweeney and her children was planned for Saturday in Concord.
Sean Sweeney, the husband of Kassandra Sweeney, spoke out against his “name being dragged through the mud” in a Facebook post against rumours of his involvement in the murder.
“I wanted to thank everyone for the outreach and support, while things will never be ‘normal’ again my body finally shut down and let me get some sleep last night and I woke up feeling as ‘normal’ as possible,” he wrote.
“Thank you to everyone who has spent the last few days ensuring that the random idiots online are properly informed and while I still am unable to confirm anything as to what happened and who is responsible,” he said.
He said he is “beyond words to those who just know better and are stopping my name from being dragged through the mud”.
He called his wife “beautiful” and “the most amazing, caring, sweetest all around good person that anyone could ever meet and just how much she loved our boys”.
A GoFundMe was launched to help with memorial services by the woman’s cousin. It reached more than $47,000 by Friday morning.
“My cousin Kassandra, one of the most genuine and beautiful people you could ever meet, and her two beautiful baby boys were taken from us,” it said.
“Our family is beyond devastated.”