It was Barine Deezias word against that of the Lincoln Police Department.

Deezia, 36, sat in a Nebraska courtroom earlier this month and testified that he was not guilty of obstructing police or resisting arrest during a March incident in which officers threw him to the ground and broke his shoulder. A few minutes before the scuffle, they had approached Deezia and his friends to ask about a companion who appeared visibly intoxicated. Officers say Deezia interfered and ultimately resisted arrest when they returned to question his friend. But Deezia claims the police used excessive force on him when they smashed his face against a glass door and slammed him onto a brick walkway.

Video evidence is supposed to provide an objective record of the facts when police, defendants and witnesses present opposing narratives of confrontations like this. Thats just one reason body cameras have arisen as a rare point of agreement in the debate over police reform. But as the technology has grown in popularity around the U.S., cases like Deezias show why its an imperfect solution for issues of transparency and accountability.

The officers who arrested Deezia were equipped with body cameras, but police say they werent activated during the incident. At least one body camera was turned on during an initial encounter with Deezia. However, it was off when the officers engaged with the group and the altercation escalated minutes later. The Lincoln Police Department released surveillance footage that appears to show a piece of the scene unfold, but also omits the key moment.

With little evidence to go on, it took the jury only an hour to reach a verdict in Deezias case: not guilty on all charges. His excessive force lawsuit against the city is still pending.

Without the body cameras, they couldnt take one persons word over the other, Seth Morris, Deezias attorney, told The Huffington Post.

The fact that the body camera hadnt been reactivated was a key point of concern for the jury, Morris said. Although the Lincoln Police Department hasnt crafted an official policy on using the cameras, Morris said it was suspicious that the officer had initially remembered to turn on the camera, only to forget later.

No matter what did or didnt happen, it just seems like youre trying to hide something at that point, he said.

Still, it could have turned out much differently for Deezia. Jurors often arent so skeptical of police. When asked to choose between a defendants word and an officers, many will simply side with law enforcement.

As the American Civil Liberties Union of Massachusetts and University of California, Berkeley, School of Law argue in a report published Tuesday , this point further underscores just how important it is for police to use body cameras correctly. Such forms of monitoring are supposed to create an unbiased account of what was said and done by each party, which proponents say can keep officers and civilians honest.

But as the devices have spread to police departments around the nation, there have been a number of incidents in which officers have failed to record critical incidents, including fatal shootings . Weak or nonexistent disciplinary rules for officers who fail to abide by body camera policies have compounded these problems.

The ACLU/Berkeley Law report says courts at the state level should pressure police by instructing juries to disregard any testimony given by an officer deemed to have not recorded an incident or to have tampered with footage in a deliberate attempt to conceal the truth. If the jury were to conclude that an officers failure to record was unreasonable but not malicious the court would instruct the jury to devalue that officers testimony and infer that the video would have been beneficial to the defendant.

Courts have a special interest in ensuring that theres footage available, because theyre the ones responsible for making sure juries reach accurate decisions and dont lock someone up who doesnt deserve to be there, said Catherine Crump, acting director of the Samuelson Law, Technology & Public Policy Clinic at Berkeley Law and a co-author of the report.

If they start imposing those types of consequences, police departments will take more seriously the risk that if you dont turn these things on, then youre not going to be able to achieve your law enforcement objective, she added.