There are two key takeaways from Samuel DuBose’s unnecessary and tragic death at the hands of University of Cincinnati police officer Ray Tensing: 1) body cameras can play a crucial role in police misconduct investigations, and 2) even police officers wearing body cameras can behave poorly.

To be sure, DuBose’s killing is not the first time that body camera footage has proven instrumental in bringing charges against police officers.

One of the best known examples is the killing of James Boyd, a homeless paranoid schizophrenic who was shot and killed in the foothills of the Sandia Mountains by Albuquerque Police Department officers. The shooting was filmed by body cameras. A special prosecutor is pursuing second-degree murder charges against two of the officers involved in the incident.

The Bernalillo County, New Mexico district attorney, who initially pursued murder charges before being disqualified from the case, said when speaking about the charges that, “We have evidence in this case to establish probable cause we didn’t have in other cases.”

Similarly, when Hamilton County, Ohio prosecutor Joe Deters announced the murder and voluntary manslaughter charges against Ray Tensing he described the body camera video as “invaluable.”

On Wednesday The Washington Post, which this year is tracking deadly police shootings, reported that of the 558 fatal police shootings in America in 2015 (the figure is now 559) only four have resulted in criminal charges against the officer.

All four of these shootings were caught on camera.

It is of course the case that some of the 558 fatal police shootings were justified. Indeed, body camera footage has vindicated officers who have killed people. Police officers do regrettably have to use their weapons sometimes. But the more widespread use of body cameras will make it easier for the American public to better understand how police officers do their jobs and under what circumstances they feel that it is necessary to resort to deadly force.

It is very likely that body cameras will be more widely used by American police. There is “overwhelming” public support for police body cameras and lawmakers in many states have introduced legislation outlining body camera policies. Michael White, a professor in the School of Criminology and Criminal Justice at Arizona State and author of a Department of Justice report on the effects of body cameras, believes that every law enforcement agency with at least fifty officers will be equipped with body cameras “within two or three years.”

But, as the DuBose shooting highlights, the use of body cameras does not prevent police misconduct from taking place. While there are certainly incidents of police officers with body cameras behaving appallingly, there is some encouraging but not definitively conclusive research suggesting that cameras do improve police officers’ behavior.

Although conducted with small sample sizes, studies on the use of police body cameras in Rialto, California and Mesa, Arizona both found that the use of body cameras was followed by drops in use-of-force incidents and complaints compared to the previous 12 months. It is the case that the small sample sizes, locations of the studies, and other factors (such as a relatively new Rialto police chief overseeing the body camera study) mean that we should be wary of making overly generalized claims based on the Rialto and Mesa experiences. Nonetheless, lawmakers and regulators should note that the deployment of body cameras is consistently followed by welcome results.

Even if it was the case that body cameras had no impact on police behavior they would still be worth using if only for the valuable evidence they can provide. Without body camera footage it is possible that officials would have believed Tensing, who falsely stated that DuBose had dragged him with his car.

It is important to remember that body cameras capture a wide range of behavior, both good and bad. The increased use of body cameras will lead to good police officers being more widely praised for their conduct. These officers should not fear body cameras. The same cannot be said of officers who unjustifiably use lethal force.