Shortly after 3:30 p.m. Wednesday, Duncan pressed an intercom button at a side door at the precinct house on Imperial Beach Boulevard, said sheriff’s homicide Lt. Glenn Giannantonio.
When a deputy answered, Duncan, who was holding two toddlers, announced he had just killed his spouse of three years, according to the lieutenant.
The mortally wounded victim was found lying on the ground on the west side of the substation. She died a short time later.
“He stabbed her repeatedly in the arm, chest, back of the head approximately 15 times,” said Minahan.
Duncan, 59, was detained for questioning and later arrested. The children, who were unharmed, were taken into protective custody.
Minahan said Duncan may have been motivated by the couple’s separation.
“Prior to the murder, the defendant was upset in regards to the separation with the victim as well as the child custody arrangement,” said Minahan.
Duncan will be back in court Feb. 21 for a readiness conference and Feb. 25 for a preliminary hearing.