The two journalists killed during a live TV report were both shot in the head.
Reporter Alison Parker, 24, and cameraman Adam Ward, 27, died of gunshot wounds to the head and body, a Virginia coroner said.
Their former colleague Vester Flanagan shot himself when police caught up with him three hours from the scene of the killings.
The gunman who killed two US journalists handed his news director a cross and said "you'll need this" when he was fired by the station, it has been revealed.
WDBJ President Jeffrey Marks told a press conference that Vester Flanagan had "reacted angrily" to his dismissal in February 2013.
Mr Marks said Flanagan told staff they would have to call the police "because he was going to make a stink and it was going to be in the headlines".
"On the way out he handed a wooden cross to the news director...and he said you'll need this," Mr Marks told reporters.
"He also made a derogatory comment to (shooting victim) Adam Ward."
Vicki Gardner, who was being interviewed live on-air when a gunmen shot two journalists has been released from hospital.
In a 23-page fax, Vester Flanagan said he was a "human powder keg waiting to go boom" before he slayed Alison Parker and Adam Ward.
Police confirmed Vester Flanagan shot himself hours after killing two former colleagues Alison Parker and Adam Ward on live TV.