A 15-year-old was shot to death in the stairwell of his Queens building Saturday afternoon, police said.

Cops found Trevor Rudd’s body — with gunshot wounds to his torso — on the second floor stairway of the Beach 41st Street Houses on Beach Channel Drive in Edgemere around 1:30 p.m..

First responders pronounced him dead on scene.

A 31-year-old man was taken into custody and a gun has been recovered, cops said. Rudd’s relationship to the suspect is unclear.

The motive for the shooting was also not immediately known.