Many of us take to Twitter or Facebook to share the joys of life. Our digital connectedness makes it easy to update others on the birth of a grandchild, a big job promotion or the perfect vacation.

Sadly, it also provides a potentially high-profile channel for those filled with hate and rage, from anonymous online commenters to terrorists in the Middle East and a coldblooded killer at a shopping mall in Virginia.

Wednesday’s televised, videotaped and essentially live-tweeted killings of TV reporter Alison Parker and cameraman Adam Ward as they conducted an interview at a mall in Moneta, Va., represented what The New York Times rightly described as “a horrific turn in the national intersection of video, violence and social media.”

Officials said a former reporter who had been fired by the Virginia TV station killed Parker and Ward and wounded their interview subject, Vicki Gardner. The shooter was identified as Vester Lee Flanagan II, who had appeared on WDBJ-TV as Bryce Williams. Flanagan recorded the attack himself and posted the video on social media after fleeing the scene. He also tweeted, “I filmed the shooting see Facebook.”

Viewers saw a gunman standing near the victims but apparently waiting until they were on the air before opening fire. The station’s footage shows Parker interviewing Gardner — and not noticing the gunman — before shots ring out and Parker begins to scream and run from the shooter. Authorities said Flanagan fled and led troopers on a high-speed chase before he shot himself in the head and ran off the road. He later died at a hospital.

A station executive described Flanagan as an “unhappy man” who had to have a police escort from the station after being fired. Before the shooting, he had used his Twitter account to describe workplace conflicts with Parker and Ward, and he had filed an Equal Employment Opportunity Commission (EEOC) complaint alleging that he was a victim of racism at the station. Jeffrey Marks, WDJB president and general manager, said the EEOC complaint had been dismissed.

We’ll likely learn a lot more about Flanagan and his possible motives in the days ahead. For now, we’re left with yet another chilling videotaped reminder that the same social media outlets that can make us feel closer to others can also be co-opted by monsters intent on doing harm.