With first-degree manslaughter charges filed against Betty Shelby, the Tulsa, Oklahoma, police officer who shot and killed Terence Crutcher, there is now a clear, recurring theme in wrongful police shooting cases: video — be it from a body cam, cell phone or dashboard footage — actually works for holding police liable for their actions.

You should get in on this trend if police not killing everybody is something that matters to you.

Why? Because there's something very special that happens when the camera's on: people start to act within reason. When they're aware others are watching, and that what they do could be used as evidence against them, they tend to consider their actions a bit more.

They become accountable. Their behavior changes.

This phenomenon was recently demonstrated in a landmark experiment from the University of Cambridge which found that police behaved more conservatively and in line with their training when they were made to wear body cameras. The knowledge that they were being recorded created a certain “self-awareness” that altered their behavior for the better.

"Technology," the study's authors concluded, "is most effective at preventing escalation of violence, both by the police and towards the police."

And if things do escalate — and they will — at least they'll be caught on tape.

It's not hard to see how this camera-induced accountability could save lives, or avenge the ones that are lost to police shootings.

The knowledge that cameras change behavior is especially important in the type of "their word against mine" scenarios many victims find themselves in the wake of police brutality — since actions speak, or in these cases scream — louder than words, law enforcement's often-fabricated stories of the events that unfolded can be invalidated when there's footage that tells a story different than the one they offer up.

This has real, tangible consequences in a time where victims of police brutality so rarely get justice: when there's clear video footage of an altercation, charges are more likely to be brought against officers who wrongly kill. In fact, in several recent headline cases, video has actually led to charges like manslaughter and homicide against police who shoot and kill.

Crutcher's case was one. The wrongful deaths of unarmed black men such as Samuel DuBose in Cincinnati, Walter Scott in North Charleston and Laquan McDonald in Chicago have also turned up charges against the police officers who killed them as well, all thanks to incriminating footage from dash cams, security tapes and body cams.

It's unclear whether these charges will lead to actual convictions, but the charges themselves do matter. While a charge isn't as good as a guilty conviction, it at least it acknowledges police culpability, and the use of excessive force.

Of course, video isn't perfect. Some footage is shaky or from an angle that doesn't show what actually happened. There are still issues with how the public can access video obtained by and of the police, too. In North Carolina, where police shot and killed Keith Lamont Scott, local law enforcement still has yet to release video of the shooting to the public. And then there are the valid and numerous concerns of privacy, how and when officers can turn cameras on, and cases where cameras don’t work or aren't in the right position.

Things can definitely go wrong. But, they can also go right. Your willingness to film an interaction with police could be the reason someone goes to, or stays out of jail.

We know what you're thinking and, yeah … it's completely legal to film the police.

Lower federal courts have generally said that the First Amendment protects your right to record and photograph police, as long as it's in public view. Some restrictions may be constitutional, but simply prohibiting the recording because the person is recording the police is not.

The police will almost invariably tell you otherwise. It's not uncommon for them to ask bystanders to stop recording, or to demand that they do.

What should you say if they do?

First of all, if you're in a public place, like the side of the road or on the sidewalk in your neighborhood, they shouldn’t ask.

“As a basic principle, we can’t tell you to stop recording,” Delroy Burton, chairman of D.C.’s metropolitan police union and a 21-year veteran on the force told The Atlantic. “If you’re standing across the street videotaping, and I’m in a public place, carrying out my public functions, [then] I’m subject to recording, and there’s nothing legally the police officer can do to stop you from recording.”

“What you don’t have a right to do is interfere,” he says. “Record from a distance, stay out of the scene, and the officer doesn’t have the right to come over and take your camera, confiscate it.”

So if you're pulled over; if you see something happening; or if you're in a situation where you feel unsafe, whip out that Samsung Galaxy Note7 and start recording. It won't solve everything (most of all the institutionalized beliefs and biases at the root of police brutality) but, one thing's for sure: it sure seems effective at holding cops accountable. And until law enforcement addresses their problems with excessive force and figures out how to stop shooting everything that moves under the auspice of their own power, that'll do, pig. That'll do.