Police line do not cross
Police have launched a criminal investigation after an officer was caught beating an alleged jaywalker (file photo) Reuters

Authorities in California have launched a criminal investigation into the "disturbing" actions of a Sacramento police officer who was caught on video slamming a man accused of jaywalking to the ground and punching him repeatedly.

The officer, a two-year member of the department, has been placed on leave as an administrative investigation into the incident was opened.

"The actions of the involved Sacramento police officer are disturbing and do not appear to be reasonable based upon the circumstances," Sacramento Police Department said in a statement.

According to The Los Angeles Times, the police department released dashcam footage from the officer's patrol cruiser of the incident on Tuesday (11 April). A cellphone video taken by a witness caused a public backlash after it went viral on social media.

The incident occurred Monday (10 April) shortly after 5pm PST (1am BST) as the man, who has been identified as 24-year-old Nandi Cain Jr, allegedly crossed a street illegally in North Sacramento. Police said Cain and the officer began arguing in the street as he attempted to walk away.

Cain asked the officer why he was being stopped. The officer responded: "You are jaywalking back here." According to the Times, Cain told the officer he looked both ways before crossing.

"Stop right now before I take you to the ground," the officer said. "If you do not stop right now, I will take you to the ground." Cain argued with the officer and said he was pulled over "for nothing".

The officer then ordered Cain to get on the ground. Cain replied: "I don't have nothing", before removing his jacket.

In an interview with KTXL-TV, Cain said the officer ordered him to remove his hands from his pocket and show him a weapon. "So I took off my jacket to let him know, 'I don't have anything,'" he said. Cain said the officer had his hand on his gun, which made him nervous.

Policeman: 'I'll break your arm'

Dashcam footage shows the officer continuing to order Cain to the ground. Cain then told the officer, "If you're a real man, you can take your gun away and you can fight me like a real man." The officer charged towards Cain, threw him to the ground and began punching him in the head.

"I am in a fight," the officer screamed. "Give me your hand. I'll break your arm." Footage shows the officer punching Cain at least a dozen times before another squad car arrived and a second officer ran to help. "Why could you just not comply?" the officer said. "You were jaywalking."

Warning: Video contains scenes of violence and strong language which may upset some viewers.

Posted by Naomi Montaie on Monday, April 10, 2017

Cellphone footage taken by a witness, identified by the Times as Naomi Montaie, shows the officer and Cain squaring off in the middle of the street. Montaie tried to get Cain to listen before the officer charged at him and began punching his face. Montaie, Cain's neighbour, can be heard yelling: "Why you beating him like that?"

Cain told KTXL-TV that once the officer brought him to the ground, he did not resist. "I am not going to give this man any reason to kill me, basically to gun me down," he said. He was arrested on suspicion of resisting arrest and for a misdemeanour warrant from Fresno County, authorities said.

Significant policy concerns

Police said a supervisor reviewed the officer's dashcam video after Cain was detained and launched an investigation. "The preliminary investigation led the supervisor to believe that there were significant policy concerns and [he] immediately notified his chain of command."

Authorities said Cain was released from custody and charges were dropped, the Washington Post reported. He will still need to appear in court for the misdemeanour warrant from Fresno County.

According to the Times, once the criminal investigation into the officer is completed, detectives will send their reports and any evidence to the Sacramento County district attorney, who will decide whether or not to press charges. Police also intend to investigate Cain's actions and present their findings to prosecutors.