The shooting deaths of two journalists has combined social media, live television and US gun violence in a crime which has horrified the world.

As America wrestles with the question of gun control, another two families are grieving over the shocking deaths of their loved ones. But this latest episode has a decidedly 21st century complexion, commentators say, with social media used by the gunman to broadcast his rampage in real time and live television cameras beaming the events back to the studio and out to viewers.

The role technology played in the crime does not end there. Still images from the dead cameraman’s equipment were used to identify the shooter, and the signal from his mobile telephone was reportedly used by police to track him.

Click the owl to read about the victims’ colleagues and loved ones  

The live stream of the shootings was shared on video app Periscope and spread rapidly across the internet. Compounding the tragedy, the victims both had partners who worked for the television station and both were at work when the shootings took place.

US media is reporting that cameraman Adam Ward’s fiancee watched his brutal killing from the control room at Virginia TV station WDBJ7. The partner of reporter Alison Parker, 24, is an anchor at the station.

Gunman a former colleague

The gunman is believed to be a disgruntled former employee of a local TV station.

Vester Lee Flanagan, also known as Bryce Williams, fatally shot reporter Alison Parker, 24, her cameraman Adam Ward, 27 and their interviewee at close range as they filmed an on-air segment in the state of Virginia.

Williams escaped the scene, triggering a state-wide manhunt as for several hours he commented via media outlets on the murders.

Police reportedly tracked his smartphone. When officers gave chase to the vehicle he was driving, Williams shot himself, dying hours later in hospital.

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“You send people into war zones and into dangerous situations, into riots and you worry that they’re going to get hurt,” WDBJ general manager Jeffrey Marks, the dead employees’ boss, told CNN.

“You send somebody out to do a story on tourism, and this — how can you ever expect something like this to happen?”

Ms Parker was interviewing local chamber of commerce official Vicki Gardner, who suffered a non-life threatening injury during the attack.

Deaths live streamed

Before Williams’ suicide, a person claiming to be him posted video footage appearing to be from the scene. In it, an African-American man approaches the reporter, cameraman and interviewee armed with a black pistol. He pauses for several seconds, watching, then fires multiple times. Ms Parker and her interviewee scream.

Later, a person claiming to be Williams sent 23 pages of text to American media outlet ABC News. The manifesto claimed many motivations for the shooting, including sexual discrimination, workplace bullying and racism.

“The church shooting was the tipping point … but my anger has been building steadily … I’ve been a human powder keg for a while … just waiting to go BOOM!” it said.

A person claiming to be Williams also called ABC News, saying police were “all over the place” looking for him.

“We’re just very saddened and just sickened … by this horrific event,” Roanoke mayor David Bowers told CNN.

Virginia Governor Terry McAuliffe said on Twitter he was “heartbroken over [the] senseless murders.”

The WDBJ television station is located in the southern Virginia city of Roanoke.

Australian ABC correspondent Nick Hamsen reports from the scene

It is very sombre here, but also very professional. I have spoken to one of the cameramen at WDBJ and these people have just lost friends, colleagues, in some cases lovers in this building and yet they are continuing to work.

They know it is difficult, but they believe that what they are doing is something important, and they believe that this reporter and cameraman were carrying out their jobs right up until the final moment.

Their job is a difficult one; it is to mourn and remember their colleagues, but also to represent them and to continue doing their job.

The partner of the journalist Alison, he anchors the nightly news — he is not on air tonight, but he was out tweeting about her today.

The producer of the breakfast program, who was the fiancee of the cameraman who was shot, she continued to put the program to air after her fiancee had been shot, and she didn’t know what was going on. So some remarkable professionalism.

And when you consider that the cameraman managed to capture a fleeting shot of this gunman as he approached — as he turned and the camera fell — he has helped identify this man for his colleagues and for the authorities, and so the news director here put it that it was perhaps his final act of journalism.

* Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14 or Suicide Call Back Service 1300 659 467