A woman armed with a 13-inch kitchen knife killed her 6-year-old son by slashing his throat early Saturday, then turned the weapon on herself, Gloucester County authorities said.

It was not immediately clear what spurred Martina Harding, 42, to attack her son inside their Deptford Township home, authorities said. Harding's husband — who authorities say witnessed at least part of the attack — and the couple's 9-year-old daughter were also home at the time but were not injured.

Martina Harding underwent surgery for a throat wound at Cooper Medical Center in Camden and was expected to recover from her injuries. She was charged Saturday night with first-degree murder, aggravated assault, child endangerment and weapons offenses.

When police arrived at the home around 7:30 a.m., they found Harding's son, Jared, bleeding profusely in the living room. He was taken to Underwood-Memorial Hospital in Woodbury, where he died a short time later.

Neither police nor the state Division of Youth and Family Services — which will launch an investigation due to the boy's death — had been called to the home in the past.