Police in Long Beach, California have opened an internal investigation about an incident involving a suspect who was tasered and brutally beaten by police even after he had been successfully subdued. According to the Los Angeles Times, 46-year-old Porfirio Santos-Lopez' teeth were knocked out, his right arm was broken, his left lung collapsed and both of his legs had gashes requiring stitches.

Witnesses said that Santos-Lopez was one of two men involved in a fight outside of a liquor store in the Locust Avenue area. Police later identified a man on surveillance tape from the store as Santos-Lopez and say the video shows him striking another man in the head.

When police approached Santoz-Lopez shortly after 6:00 p.m. on Monday, he was reportedly acting irrational and not responding to officer instructions. In witness video -- which later appeared on YouTube -- police can be observed tasing and beating him with tactical batons, then continuing to do so once he was lying on his back on the street.

"It is too early to make any judgments," said Police Chief Jim McDonnell to the Times. "The YouTube video is certainly disturbing. Any time you see someone hit with the baton, there is level of discomfort."

Long Beach Police Sergeant Aaron Eaton said that police officers attacked Santos-Lopez a second time because he refused to roll on to his stomach after he fell to the pavement.

"It wasn't that he couldn't understand," Eaton said. "He refused to go on his stomach."

After being taken into custody, the suspect was taken to Long Beach Memorial Medical Center, where doctors re-inflated his left lung and splinted his broken bones. Santos-Lopez' partner Lee Ann Hernandez told the Times that Santos-Lopez had been drinking before the incident, but contrary to what he said to police at the scene, he had not been using drugs.

Hernandez said that Santos-Lopez had been exhibiting signs of mental illness in the months leading up to the incident, hearing voices and becoming increasingly paranoid. He repeatedly called police and paramedics and begged to be taken to a psychiatric facility, but they refused, saying that Santos-Lopez was not a danger to himself.

"They had no right to beat him up like that," she said. "They don't need to be doing that to someone like that."

Watch video about this story, embedded below via the L.A. Times:

Watch the beating video, embedded below via YouTube: