On Tuesday (April 7) news broke that a white police officer in North Charleston, South Carolina would be charged with murder after a cell phone video sent to the New York Times showed him chasing and shooting an apparently unarmed black man.

That unarmed black man was Walter Scott, and he had been stopped for a broken taillight.

Officer Michael Slager said that he feared for his life after Walter Scott took his stun gun away from him, but the video clearly shows Walter running away, unarmed, while the officer fires at him eight times. The footage also shows an object that appears to be a stun gun falling to the ground before Walter Scott ran away, and then shows officer Slager moving that object and placing it near the body of Walter Scott.

Following the killings by white police officers of unarmed black men like Eric Garner in New York, Michael Brown in Missouri, and twelve-year-old Tamir Rice in Ohio, this news might make it seem like there’s a crazy new pattern of racism and police brutality emerging.

But what if these sorts of things have always gone on, and the only difference is that now we're using our phones to create evidence?

Wednesday morning Walter Scott’s family appeared teary-eyed on NBC’s “Today” show and said they were certain that no charges would have been filed if the cell phone video didn’t exist. “It would have never come to light,” said Walter Scott Sr., “They would have swept it under the rug, like they did with many others.”

Protestors at City Hall in North Charleston this morning carried signs with slogans like, “The whole world is watching,” and “Back turned, don’t shoot.” One protester got on the loudspeaker and said, “This has been a reality that has been in the North Charleston Police Department for many, many years. It just so happens we got a video.”

Walter Scott's family, the media, and the internet seem to be largely in agreement that if the video didn't exist, officer Slager would not be facing murder charges right now.

So, 2 Questions:

1. Does this mean we should film every police interaction we see?

2. Are we even allowed to do that?

To get some answers, MTV News spoke with Jay Stanley, a Senior Policy Analyst for the ACLU, about our right to film police interactions, how to stay safe if you’re doing so, and what to definitely NEVER DO when interacting police officers.

“Recording police interactions can definitely help us protect ourselves,” Stanley told MTV News. “And I think it’s opening the eyes of a lot of people. The ubiquity of camera phones and online video has made a lot of people who don't get harassed by police aware in a new way of what can go on [between police officers and citizens]. As we saw in the case of Eric Garner, having something on film doesn’t always guarantee justice. But I think that historically, jurors and judges have usually been inclined to just take the word of a uniformed police officer over that of an accused criminal. Now a lot of times we have actual evidence that shows the other side.”

According to the ACLU website, “Taking photographs of things that are plainly visible from public spaces is a constitutional right--and that includes federal buildings, transportation facilities, and police and other government officials carrying out their duties. Unfortunately, there is a widespread, continuing pattern of law enforcement officers ordering people to stop taking photographs from public places, and harassing, detaining and arresting those who fail to comply.”

Stanley also notes that police officers are trained to take control of any out-of-hand situation, so it isn’t uncommon for them to boss people around and tell people to stop filming, even though they’re not legally permitted to do so. “Police officers are able to order people around to a certain extent to gain control of a situation," he said, "But there’s a limit to what they’re allowed to make people do. They can’t tell you to drop and do 50 pushups, and they can’t tell you to stop filming or photographing, either.”

Stanley continues that while it is your right to film in public space, you still need to respect police if they ask you about it. “If an officer demands that you stop filming or photographing something in a public space, you should politely but firmly defend your rights,” Stanley told MTV News. “Don’t ever interfere with legitimate policing activities, and never physically resist an officer. Don’t become rude or defiant, but do respectfully tell the officer that you have a constitutional right under the First Amendment to film or photograph what’s going on.”

“If a police officer tells you that they need your footage for evidence,” Stanley added, “offer to email it to them. You should never physically resist a police officer, but legally you do not have to give your cell phone or camera to an officer if they demand it.”

In regards to that evidence, the ACLU website notes that, “Police may not delete your photographs or video under any circumstances. Officers have faced felony charges of evidence tampering as well as obstruction and theft for taking a photographer’s memory card.”

So if you're wondering whether you should record an interaction you witness between a police officer and a citizen, the answer is this: If you're in a public space, you have the right to record what's happening, but always consider your safety first. Police officers are not allowed to tell you to stop filming or to take away your camera or your phone. If they demand that you stop or hand over your phone, you should politely and respectfully defend your rights, but you should never interfere with legitimate policing activities or physically resist a police officer.

For more information about your right to free speech, visit the ACLU's website.