Cops are looking for the gun-toting thug who can be seen in this dramatic video fatally shooting a teen in Brooklyn.

The suspect calmly rode in the elevator with Andre Pitts, 18, around 7:30 p.m. Sunday and as soon as they both exited on the fourth-floor of the Brownsville building, he began shooting.

Pitts was shot in the chest and died at Brookdale Hospital.

The alleged killer then headed back on the elevator and was seen on surveillance video walking away with his head held high.

He was described as being about 5’8″ tall and he wore a black jacket with a green hood with green, white and red stripes on the sleeves, cops said.