A hotheaded Queens, New York bodybuilder killed his dog by tossing it out of a third-floor window – then played dumb, telling cops he was asleep the whole time.

Milan Rysa, 30, hurled Brooklyn, a Chinese Shar-Pei weighing about 50 pounds, out of his apartment window in Astoria, Queens as he played thumping dance music about 8:30 p.m Monday witnesses said.

“I saw it coming out the window,” a shocked witness said. “I heard the yelp when it hit the ground. I heard the thud. It just missed a woman.”

Witnesses said Rysa looked out the window, saw a crowd gathering near Brooklyn’s broken body, then shut off the music and the apartment’s lights.

Cops, not sure what they would encounter inside the apartment, armed themselves with a battering ram and bulletproof shields.

But Rysa eventually opened the door and claimed he was just catching some shut-eye. He was booked for aggravated animal cruelty and reckless endangerment, and taken to Elmhurst Queens Hospital Center for a psychiatric evaluation.

His Facebook page abounds with shirtless, beefcake photos of himself. But it also includes an album called “My Lil Bad Boy” that shows Brooklyn as an adorable puppy.

Neighbors had no idea what prompted the heinous crime, but several said they had previously seen Rysa abuse the animal, keeping him in the public hallway outside his apartment, fenced in by a toddler gate.

Rysa also let Brooklyn relieve itself on the roof. He would fling the dog’s feces onto nearby rooftops, then leave the dog unattended for hours, the hot rooftop burning his paws, one neighbor said.

“The poor thing wanted to play all the time,” the neighbor said.