Police searching part of I-93 in New Hampshire for evidence in deaths of mother, 2 young sons

CONCORD, N.H. - State and local police investigating the shooting deaths of a mother and her two young sons are searching a large area of Route 93 in New Hampshire for evidence.

Twenty-five-year-old Kassandra Sweeney, her 4-year-old son Benjamin and 1-year-old son Mason were found dead in their home on Wethersfield Drive in Northfield exactly one week ago on August 3.

Autopsies showed each died from a single gunshot wound and the medical examiner ruled all three deaths as homicides.

There have been no arrests, but Attorney General John Formella said investigators have identified everyone involved in the shooting deaths and there's no threat to the public. When asked last week if police had the weapon involved, Formella said he could not comment.

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In a statement Wednesday, his office said investigators will be "in the area of Route 93 between exits 17 and 20 in Concord, Canterbury, and Tilton," looking for "physical evidence."

"The search activity is not the result of new information in the case but is part of the ongoing investigative process," Formella said in the statement. "Officials ask that the public follow all road signage in the area and provide investigators appropriate space to complete their work."