A judge has declared a mistrial in the case of a former policeman accused of assaulting a handcuffed black teenager during a rough videotaped arrest in the Los Angeles suburb of Inglewood last year after the jury remained deadlocked.
The jury said it was hopelessly split with five of the 12 member panel holding out for a not guilty verdict for white former police officer Mr Jeremy Morse, 25.
The trial has been closely watched in Los Angeles amid fears that that a verdict clearing the officer could stir violent protests in the city's African-American community.
Judge William Hollingsworth declared a mistrial, prompting cries of "There is no justice here" and "Pig" from two black activists in the tense courtroom.
The jury, which had been deliberating since Thursday last week, found Mr Morse's former partner Mr Bijan Darvish not guilty of filing a false police report that failed to mention the incident.
The arrest in July last year of then 16 year-old Mr Donovan Jackson was caught by a bystander on videotape, evoking memories of the 1991 beating by four Los Angeles police officers of black motorist Mr Rodney King. The subsequent acquittal of those officers in 1992 provoked the worst riots in modern US history.
In last year's videotape Mr Morse was seen slamming Mr Jackson's head and upper body on to the trunk of a police patrol car and punching him in the face while he was handcuffed.
Race was not mentioned as a factor in the current trial but police and community leaders have nevertheless been working hard to allay any unrest resulting from the verdict.
Authorities were given four hours notice that a verdict had been reached on Tuesday before it was read out in court in order to get some 1,500 volunteer "peace ambassadors" fanned out onto the streets on Inglewood - the largely black suburb of Los Angeles where Mr Jackson was arrested last year.
Prosecutors said they would be back in court on September 22 to determine whether Morse would be retried.