This screenshot from WDBJ-TV7, in Roanoke, Va., shows reporter Alison Parker and photographer Adam Ward. Parker and Ward were killed, Wednesday, Aug. 26, 2015, when a gunman opened fire during a live on-air interview in Moneta, Va. (Courtesy of WDBJ-TV7 via AP)

NBC reports suspect in on-air shooting posted to social media

The suspect believed to have shot a reporter and cameraman to death on live television in Virginia was identified as a disgruntled former em…