Gun homicides are not unusual in the United States, but what happened in Roanoke, Va., yesterday is rare — killings on live television that were then immediately posted on social media feeds.

The clips of on-air journalist Alison Parker and photographer Adam Ward being gunned down while on their station's morning show and filmed from two perspectives, including the killer's, went viral.

Some are calling it a turning point in the internet age: National Review writer Charles C. Cooke's online piece called it "America's first social media murder." 

Social media were initially used in the sad sequence of events to circulate the breaking news itself. Then, footage of the broadcast, essentially of the murders, spread on Twitter and Facebook. Next, the suspect used social media — while on the run from police —  to upload his own chilling video of the crime and shed light on his motive. 

Some social media users expressed the day showed the best and worst possible uses of the platforms. While they were useful for spreading news and providing an outlet for people to share their shock and condolences, they were also used to show the shooting deaths of two innocent people.

"The tools of the digital age, like all technologies, are morally neutral. They can be used to inform, inspire and console. And we learn again today that they can be used with murderous rage to blot out everything that is human and decent," Roy Peter Clark of the Poynter journalism institute wrote online.

The shooting happened at about 6:45 a.m. while Parker was on air for WDBJ7 and Ward was behind the camera. They were interviewing Vicki Gardner at a shopping and entertainment complex when they were approached by a gunman later identified as Vester Lee Flanagan. Gardner was also shot but survived.

Flanagan, a former employee of the station who went by the name Bryce Williams on air, had been fired about two years earlier.

Video posted by gunman

The camera was on Parker and Gardner when multiple shots were fired. Parker screamed and turned to run as the camera fell to the ground. The video cut out and the anchor back at the studio came on screen and told viewers it wasn't clear what just happened.

Ward essentially filmed his own murder and Parker's, capturing the suspect's face in the process. The footage quickly began circulating on Twitter and Facebook. Newsrooms around the world, including the CBC, had to make judgment calls about what to show on air and on their websites.

Social media users were also making decisions about whether to share the video with their followers. Some on Twitter urged that it not be circulated, saying it was morally wrong and disrespectful to the victims and their families. They urged people to share photos of Parker and Ward that celebrated who they were as people and as journalists.

A few hours later, at about 11:00 a.m., the story as it played out on social media took an even more shocking and darker turn.

APTOPIX On Air Shooting

WDBJ-TV7 anchor Kimberly McBroom gets a hug from anchor Steve Grant, left, as meteorologist Leo Hirsbrunner reflects after their early-morning newscast at the station on Thursday in Roanoke. (Steve Helber/Associated Press)

A Twitter account with the handle @bryce_williams7 began tweeting. The posts singled out Parker and Ward and then: "I filmed the shooting see Facebook."

A Facebook account under the name Bryce Williams contained video, filmed from a gunman's perspective, of the incident. It clearly shows the barrel of the gun aimed at the victims.

It appears as though the social media messages were posted in the time between the shooting and when Flanagan was found in his car a few hours later with a self-inflicted gunshot wound. He died in hospital shortly afterward.

Accounts shut down

"We watched a murder on Twitter today," CNN's Brian Stelter, host of Reliable Sources, a show about the media, said on air. Journalists use live television and social media for their jobs, he said, and the gunman "used those tools against us."

Twitter and Facebook shut down the accounts linked to Bryce Williams, but that didn't put an end to duplicates of the video circulating on social media, including on YouTube. A spokeswoman for YouTube told the Washington Post the company was removing any clips as soon as they were flagged.

APTOPIX On Air Shooting

WDBJ news anchor Chris Hurst pauses while overcome with emotion and holding a photo album given to him by his girlfriend, Alison Parker, the on-air reporter killed in the live TV shootings Wednesday. (Erica Yoon/The Roanoke Times/Associated Press)

Again, some social media users urged each other not to share the video. "This is the worst possible use of Twitter/Facebook" one user wrote.

Anatoliy Gruzd, director of the research institute The Social Media Lab at Ryerson University in Toronto, said Wednesday's events highlight the pros and cons of social media.

Some users, not all, are eager to share breaking news in an effort to increase their popularity or credibility and will do so regardless of the content, he said.

'Think twice before you click the retweet button.'
- Anatoliy Gruzd, Social Media Lab

"We're living in a time when the number of re-tweets and the number of followers are treated as digital currency," he said in an interview.

Gruzd said he's not at all surprised that the suspect appears to have posted the video of the crime.

"The person was clearly aware that the audience would be there," he said.

Social media has been used before to show evidence of crimes, Gruzd said, citing the ISIS beheading videos as an example, and violence has been captured on live television plenty of times before.

What happened on Wednesday was not unique, he said, but paying attention to it is still worthwhile.

"It would be a stretch to call this the first social media murder, but I think this is a great example that highlights the importance of social media in our society in terms of disseminating breaking news and other information in real time," he said.

"And it shows that the power is not concentrated any more in the hands of a few, but in fact it's distributed across all people in the world."

Social media companies have their responsibilities in how they handle violent content, but so do their millions of users, Gruzd said. Do you click the retweet button or do you click the "flag for inappropriate content" button when videos like the ones Wednesday are circulating?

"Think twice before you click the retweet button," he advised.