"I think he's experiencing that, but he does not understand it and projects it on the world instead."
What the newly released tape and pictures do not answer is the question of why -- what could have driven Cho to go on his rampage?
Dr. Kathyrn Moss, attending psychiatrist in the Personalities Disorders Clinic at NewYork-Presbyterian/Weill Cornell, said it is unlikely that one factor alone led to Cho's behavior.
"This is a mix -- a constellation of factors that came together in a horrific way," Moss said. "It's not just one thing. It can't be."
Ragan agrees. "Usually behavior is multideterminant, meaning there's not just one thing behind it," he said.
"There are a number of elements that come together that create a situation -- and there was the perfect psychological storm to create this enormous tragedy."
Among the possible contributors to Cho's mental state could have been an underlying mental condition and a background of violence.
The tape sheds little, if any, light on the exact causes, however.
"One question I have is: Where does this preoccupation with violence come from?" Ragan said. "He is obviously enamored with weapons and violence. It is totally bizarre, the pose with the hammer. Obviously he's very serious, but he's pretty crazy."
Williams said abuse in early life can sometimes result in violent behavior later, though no such abuse has yet been found in Cho's situation.
"It is well known that men who were abused -- emotionally, physically and/or sexually -- as children are far more likely than those not abused to engage in violent behaviors as adults," Williams said.
"This makes it important to search very carefully in Cho's history, to see if there is any evidence he was abused. If so, it would help to explain how he developed into a young man with tendencies to anger and aggression."
Tendencies that would eventually lead Cho to submit to the world a terrible glimpse into his fractured psyche.
"Clearly it's a horrible way to do it," Ragan said. "It is a fusion of the egomaniacal and the criminal, and there is an absolute absence of any kind of regard for the enormous harm this inflicts on others."