SAN FRANCISCO (CBS SF) — Prosecutors in San Francisco Friday said they will not retry a man accused of battery on a police officer in a struggle with BART police that was captured on bystander video this summer.

Michael Smith, 22, was acquitted on Dec. 14 of four counts of misdemeanor battery on a police officer in connection with the July 29 incident.

READ MORE: Firm Once Owned By 'Pharma Bro' Shkreli To Pay $40 Million To Settle Price Gouging Lawsuit

Jurors hung, however, on two other counts of battery on a police officer, one count of resisting arrest and a lesser charge of simple battery, and prosecutors could have chosen to refile charges.

BART officials have said officers were responding to a 911 call from a man who claimed that a man on the train had threatened to rob him and might be armed when they confronted Smith and his girlfriend at Embarcadero Station as they exited a train.

Video of the violent arrest was released last week by the San Francisco Public Defender’s Office.

Smith was not armed during the confrontation. Upon the release of the video, Public Defender Jeff Adachi called on prosecutors to drop the remaining misdemeanor charges against Smith.

BART Police Body Cam, Surveillance and Witness Video (Warning: explicit language)

The video shows officers with guns drawn confronting Smith as he steps off a train at Embarcadero Station. Smith is seen struggling with officers who forced him down, pinning him on his stomach. BART officials said Smith bit, kicked and spit on the officers.

The incident was also captured on video by bystanders and triggered some controversy, as it appeared to show police punching Smith in the head while he was pinned on his back.

READ MORE: Oakland City Council Votes To Increase Police Staffing

Adachi, who chose to handle the case personally, has characterized the case as an example of racially biased policing, with officers overreacting to a report that turned out to be false.

He said Smith and his girlfriend had been subjected to possibly racially motivated remarks from a white male passenger, accusing the woman of smelling bad, and were attempting to get away from the man when they left the train.

Smith looked to be relatively calm until an officer also took down his girlfriend, keeping a knee in her back even after being informed she was pregnant.

Adachi said the woman, Andrea Appleton, miscarried in her first trimester as a result of the officer’s actions. “The officer had his knee in her back for 21 seconds,” he said.

BART spokeswoman Alicia Trost said an internal affairs investigation into the incident is still in progress. She declined to comment on the decision to drop the case, saying only that it was a matter for the district attorney’s office.

Adachi was not immediately available for comment.

An independent auditor found BART Police has made significant reforms since an unarmed passenger, Oscar Grant III, was fatally shot by police at the Fruitvale station in 2009.

MORE NEWS: Bay Area Remembers 1941 Attack On Pearl Harbor That Changed America Forever

TM and © Copyright 2016 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2016 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. Bay City News Service contributed to this report.