A suicidal 19-year-old was fatally shot outside his Long Island home by police, who said he was armed at the time with three handguns, one of which was allegedly aimed in their direction.

Officers with the Nassau County Sheriff’s Office responded to the Massapequa home on Stone Boulevard Friday night, said Nassau County Police commissioner Patrick Ryder. They were reportedly called to the residence by a neighbor, who feared the man who lived there, David Clements, wanted to kill himself.

The caller said he heard Clements make several suicidal comments before disappearing inside his home with what appeared to be a firearm in hand.

When officers arrived on the scene, Clements was outside again. This time he had three guns — two of which were BB guns, News 12 Long Island reported.

“He was threatening to kill himself several times,” Ryder told reporters. “The officers gave him directions to drop the weapon.”

Instead, Clements ran back inside the home, and returned with “a loaded 9mm handgun with a very bright flashlight on it.” He then “rushed down his driveway, pointing his weapon at officers until it became necessary for an officer to use deadly physical force,” said Ryder, who called it a “suicide by cop.”

An officer fatally shot Clements around 8:30 p.m., according to Patch. He was pronounced dead at the scene.

Police said Clements had a history of mental illness and access to guns.

The Nassau County Police Department Homicide Squad said it will continue its investigation into the incident in conjunction with the New York State Attorney General’s Office. The name of the officer involved was not released.