VIDEO: Violent takedown by officer in Houston

HOUSTON -- Houston officials released surveillance footage on Monday showing a violent takedown by an officer on a train platform in August.

WARNING: The video is graphic and may be upsetting to some viewers.

The video, which had no sound, showed METRO Officers J. Warren and D. Reynoso approach Darrell Giles, who appeared to be asleep on the platform.

After speaking with Giles, Warren repeatedly hit Giles with his baton.

Giles fell onto a bench and eventually onto the ground, writhing in pain. Warren continued to hit Giles, even after he fell to the ground.

Warren has resigned, officials announced during a press conference.

Reynoso appeared to intervene toward the end of the confrontation. He was cleared of wrongdoing and returned to service, although he was required to undergo additional training.

Giles was checked by medics at the scene of his arrest, but was then taken in for processing, at which point he began to complain of pain in his arms and received further medical attention.

VIDEO: Man allegedly beaten by Metro Police speaks out

Trespassing charges against Giles were dropped.

"I thought he pulled a gun out," Giles said of the altercation last month. "He hit me so hard, he knocked me to the ground, so the first couple licks, he's just standing over me going bom, bom, bom, making some noise."

"I don't remember too much. All I remember is bracing myself and just taking the licks and I was holding my arm up," Giles added.