Video of the immediate moments after police killed Manuel Diaz. In the video Diaz was still alive--and police stood there for over three minutes and did nothing. Instead, they seem more concerned with pushing witnesses away from the scene. [MORE]

From [HERE] The Ninth Circuit ordered a new trial Wednesday after a jury that heard inflammatory evidence sided with the Anaheim, California, officer who shot Manuel Diaz to death in 2012.

Diaz, 25, was killed after a short foot chase by police on July 21, 2012, sparking days of violence and street protests in Anaheim.

Nicholas Bennallack, the officer who fired the fatal shots, testified that he suspected Diaz was in a gang based on the way he dressed. Based on his experience in the area, he believed criminal activity was afoot.

Though Bennallack said he feared Diaz had a gun and was preparing to shoot him, authorities did not recover another firearm at the scene. One of the bullets Bennallack fired Diaz passed from his right buttock to his left thigh. The other entered just above and behind Diaz's right ear, exiting out the other side of his head.

Genevieve Huizar, Diaz's mother, tried to hold Anaheim and Bennallack liable for excessive force and other claims, but a federal jury ruled for the defendants after a six-day civil trial in March 2014.

The Ninth Circuit reversed that decision on Wednesday, saying an error in the trial's layout caused the jury to hear inflammatory evidence that may have improperly shaped their verdict.

By failing to split the liability phase from the compensatory-damages phase, U.S. District Judge James Selna allowed the jury to consider material that was not relevant to whether Bennallack used excessive force, the appellate panel found.

Selna had deemed evidence regarding Diaz's gang affiliation and drug use relevant as to damages because the evidence could undermine the strength of his mother's love for him and their relationship.

In making that ruling, however, Selna conceded that the evidence was irrelevant as to liability because Bennallack was not aware of either Diaz's gang affiliation or his drug use at the time of the shooting.

Wednesday's reversal notes that these pretrial rulings nevertheless failed to keep the jury from being "exposed to a copious amount of inflammatory and prejudicial evidence with little (if any) relevance." (Parentheses in original.)

Counsel for Bennallack was permitted to offer photographs of Diaz's gang tattoos, and Diaz holding a gun in his left hand and making a gang sign with his right hand.

Furthermore, a gang expert testified that gang members pose with guns in photographs to show that they have the means to commit crimes against law enforcement.

This same expert also testified that Diaz's gang moniker was "Stomper" and then repeatedly used the moniker to refer to Diaz during his testimony.

Selna had likewise allowed a drug expert to speculate as to how the high level of methamphetamine in Diaz's system at the time of the shooting may have affected his response to the police.

Writing for a three-person panel of the Ninth Circuit, U.S. Circuit Judge John Owens said this evidence "was highly likely to influence improperly the jury's evaluation of Officer Bennallack's use of force, when he never suggested he thought Diaz may have been intoxicated."

The court did formally strike some of the experts' testimony from the record, the ruling notes. At other times, the court also instructed the jury to consider certain evidence only as to whether damages should be awarded, and not as to whether Bennallack was liable for excessive force.

But Owens said no jury would be able to compartmentalize all of the information.

"The evidence of Diaz's drug use and gang affiliation has marginal, if any probative value as to damages, and none as to liability," Owens said.

Owens noted that police shootings are often the most difficult and divisive cases in the legal system, capable of perplexing "even our most experienced trial judges."

"To avoid runaway cases — like this one, where the defendants and their witnesses repeatedly overstepped the judge's rulings — courts should use bifurcation to corral lawyers and witnesses, so the jury hears only evidence to the issues at hand," he said.

"Here, that was whether Officer Bennallack acted lawfully when he shot Diaz. Because the jury heard considerable and inflammatory evidence that had nothing to do with that question, we reverse," Owens added.

Huizar's excessive-force claims must face a new trial, the court found.

"That Diaz was slowing down at the time of the shooting does not compel that he was complying with the officers' orders, nor does it prove that he was preparing to shoot the officers," Owens wrote. "These are both reasonable interpretations of the evidence. The jury was entitled to choose between them on their weighing of the evidence and the witnesses' credibility."

Anaheim spokesman Mike Lyster said the city is disappointed with the decision and "will continue to see the case through the legal process."