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 father of a US journalist shot live on-air has urged lawmakers to take action on gun control.
Andy Parker, the father of murdered WDBJ7 reporter Alison, told CNN: "I'm not going to rest until I see something happen.
"We've got to have our legislators and congressmen step up to the plate and stop being cowards about this."
Mr Parker also dismissed any argument that his daughter and Adam Ward would have been safe if they were armed.
"It wouldn't have made any difference," he said. "How many Alisons is this going to happen to before we stop it?"
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.