This is a RUSH transcript from "The O'Reilly Factor," July 20, 2012. This copy may not be in its final form and may be updated.

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BILL O'REILLY, HOST: "Back of the Book" segment tonight, ever since man walked the earth, there has been violent behavior. Part of the human condition. There's nothing any of us can do about it. However, psychotic behavior can often be predicted.

Joining us now from Boston, Dr. Keith Ablow, a psychiatrist.

So what is the headline of this story to you, Doctor?

DR. KEITH ABLOW, PSYCHIATRIST: The headline of this story, Bill, is that all such episodes of seemingly random senseless violence have roots that reach deeper than the moment, deeper than the monstrosity. They can be explained by psychopathology -- often explained by psychopathology taking root.

And what's more: that psychopathology, as it starts to manifest itself, is almost always noticed by people who disregard it, who have denial about how severe a case could be unfolding in front of him.

O'REILLY: OK. So you say that, if you got your hands on this shooter, and you put him into therapy, you could figure out why he did what he did?

ABLOW: No doubt, if I had time with Mr. Holmes and his family, we could trace the roots of his emotional instability, perhaps the early chapters in his life story.

But what's more than that, I would be able to find, as a reporter and psychiatrist, people who had touched base with Mr. Holmes and who knew that something dark was unfolding.

After all, here's a young person who was pursuing a career as a healer, wanted to be a neuroscientist, was able to complete assignments, to make out an application to be accepted to the University of Colorado to be a Ph.D. candidate. Something went wrong, and people knew. They just didn't take it -- I believe they just didn't take the signs and symptoms seriously enough, because nobody wants to believe it could be happening.

O'REILLY: Well, I don't know -- I don't know if that is quite fair. But let me get to my point here. If the ABC News report is accurate and his mother told the authorities "You have the right man" as soon as she was contacted, then the mother knew there was something wrong with her son, OK? We start there. But what...

ABLOW: Perhaps.

O'REILLY: In our society you can't do anything about it. You can talk about it. You can say to somebody, "I think that person over there is dangerous," but there's no court in the land. There isn't any psychiatrist. You can't do anything about it. So you have somebody sitting in your office, and you think that person is dangerous. You can't detain them. They can walk the streets...

ABLOW: That's not -- that's not so.

O'REILLY: OK, go. Go.

ABLOW: First of all, we've got to explore, why was this young man withdrawn or released from his studies? Was he evaluated by a student health service? Did he get a...

O'REILLY: But they can't force him to do that. If he wants to leave he can leave.

ABLOW: Yes, but he can -- but the question is what was known? What kinds of answers did he give when he said, "I'm out of here"?

O'REILLY: All right. Let's assume something is known.

ABLOW: Listen if someone is my office -- I'll tell you right now, if someone's in my office, and he says -- I'd say to him, "Listen, you tell me that you're having feelings that people don't mean you well. Would you ever take action against those people?"

Yes, he says.

I say, "OK, well, hold on a second." And I go down to my secretary's office and I say, "Call 911. I'll make out one of these forms, and we'll have this person committed."

O'REILLY: OK. And you know how long...

ABLOW: That is what I do, because I've seen bad things happen.

O'REILLY: How long that's going to -- they're not going to commit that person. If the person has a lawyer, the lawyer will come in, and the person will be out on the street. You can't...

ABLOW: Not necessarily.

O'REILLY: Very hard.

ABLOW: Not necessarily.

O'REILLY: We had a story -- we had a situation like that here in New York this week, where a guy stabbed a woman to death. And that guy has got a rap sheet all up and down his arm that he was crazy. He was on medication. The doctor -- psychiatrist said, "Look, this guy has got to take it." The guy didn't take it. Boom, the woman is dead.

They're not going to detain, in a big city like Boston or New York or Denver or San Diego. You know that. They're not going to detain. You've got to have cause to detain.

ABLOW: Bill -- Bill, it's absolutely a fractured mental health-care system; I agree with that. But that's why we have to put out the word to clinicians and family members.

O'REILLY: To do what? To do -- what could the mother have done?

ABLOW: Listen, you should hear me on the phone at times with E.R.'s, saying, "If you'd like to do that release, my patient that I just sent you, I'm going to fax you a letter that says that you're wholly responsible for that. And I'm going to outline the responses that this individual gave to me..."

O'REILLY: OK. And good for you, by the way.

ABLOW: "... that puts people at immediate peril."

O'REILLY: Again, good for you.

ABLOW: And that is the message that has to go out to others.

O'REILLY: And good for you to do that, because you're -- and I know Ablow for a lot of years. He does. But most don't, because they don't want to be sued. The guy can come back at you. There's lawyers all over the place.