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.
Donald Trump said shootings in the US are "not a gun problem, it's a mental health problem".
The presidential hopeful told CNN he did not think gun laws needed to be tightened as it was down to people.
He called Virginia shooter Vester Flanagan a "very sick man" and said more resources should be given to address mental health.
"There are so many things that can be done," he told the broadcaster.
"What happened in Virginia was very sad. [The shooter] should have been institutionalised."
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.