They were discovered just past midnight Saturday at the family’s home in Clarkstown – 18 miles north of Manhattan – after Morgan failed to show up for work at the police department in nearby Bronxville.

The Bronxville police chief, Christopher Satriale, said the killings left the department with “profoundly broken hearts at the senseless loss of innocent lives”.

A neighbor, who declined to be identified, told the New York Post that the family were “textbook, perfect American”.

Though police described Morgan’s killing of his wife and their children as a murder-suicide, such crimes since the 1980s have been known as family annihilations.

Family annihilators also often die by suicide, and common risk factors include prior domestic violence, substance abuse as well as access to guns.

However, with no centralized database for family annihilations available, the crimes’ characteristics and prevalence are generally unknown at an academic level.

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