Dramatic video emerged of San Diego cops gunning down a man who went on a deadly rampage at a poolside birthday celebration.

The footage, apparently shot from an apartment at the upscale La Jolla Crossroads complex, shows officers converging on the gunman, Peter Selis.

“Drop the gun!” one cop is heard yelling.

A second or two later, gunfire erupts as more officers run to the scene. Several shots were fired.

Selis, 49, a resident at the complex, is believed to have killed a woman and wounded seven other people.

The white shooter — who was armed with a semiautomatic pistol — targeted four black women, two black men and a Latino man.

It was unclear if race was a factor in the shooting.