Early in his medical career, psychiatrist Paul Appelbaum had a patient who worried him.
"The patient was a young man in his early 20s who already had a long history of hospitalization for psychotic episodes," Appelbaum recalls.
The young man had dropped out of high school. He had no friends. He got into fights. He lived alone, in a boarding house.
"One day, he told me how the landlady at his boarding house where he lived had been harassing him and how angry he was," Appelbaum says, "and he said in no uncertain terms he was going to take her out."
At the time, Appelbaum didn't know what to do. Today, he heads the division of psychiatry, law and ethics at Columbia University. He knows that every psychiatrist faces the challenge of predicting violence.
"It's a routine part of psychiatric practice," he says. " I think every psychiatrist and every clinic in the country, and many psychiatrists in private offices, go through that process every day."
So how can you tell who is going to be violent?
There are risk factors: making threats; a history of being abused as a child; prior acts of violence. But there haven't been enough cases of violence to the degree of what happened in Blacksburg to develop a clear profile.
Forensic psychiatrist Phillip Merideth says you can predict who is at risk of committing violence. But you can't actually say who will.
"Psychiatric literature in the past has shown that efforts to predict — and I'm using the word predict in quotes — is no better than flipping a coin," Merideth says.
Merideth is a forensic psychiatrist and the chief medical office for Brentwood Behavioral Healthcare in Mississippi. He's also a lawyer who teaches about mental health and the law. He says patients' rights must be considered.
"The thing that I worry about is the deprivation of liberty that occurs with involuntary hospitalizing someone against their will, and balancing that against the protection of the public," Merideth says.
Recently, Merideth saw a student who was scaring classmates and teachers. The student had threatened others, so Merideth could have made a case for involuntary hospitalization.
But he didn't want to.
"I was worried that this student would go back to their educational setting and be ID'ed as a mental patient and be further socially isolated," he says, "and that might lead to an exacerbation of their psychiatric condition."
Merideth recommended the student be required to get outpatient care in order to remain in school. And much to his relief, it worked out.
Years ago, Appelbaum could have hospitalized the patient who threatened his landlady. But he, too, was worried about the patient's civil liberties when he had no way to prove the man would follow through on his threat.
And there was another factor.
"Psychiatric hospitalization is an expensive resource and a scarce one," Appelbaum says. "And to use it merely because we were afraid that he might represent some degree of threat at some point in the future would not be a good use of a hospital bed."
After consulting with a supervisor, Appelbaum called the landlady, in the presence of his patient, to warn her. The landlady said she wasn't scared.
"Meanwhile, my patient was sitting across the desk from me with a little bit of a smile on his face," he recalls.
Appelbaum realized his patient wasn't really planning on hurting his landlady. In this case, he just wanted the threat to be communicated. The fact is, it's easy to be suspicious of patients. But the vast majority don't hurt anyone.