Killers seldom meet the legal standard for insanity, which is quite different from the way most people use the word every day. Killers may be disturbed, but that doesn't necessarily mean that they can't tell right from wrong or are compelled to maim or murder.

I like to have success experiences rather than failure experiences. So I'm more likely to compete in things I'm good at, and more likely to spend time on the things I expect to succeed at.

One of the few times I'm hit emotionally is when I listen to the tapes sadists make of torturing their victims. There the person is currently suffering, you can hear them suffer, and that calls out for an empathic response. But when they're dead, when they're no longer suffering, when it's over, it's hard to feel empathetic for the corpse.

Consider surgeons and their work. It's unthinkable to put your hands in the warm blood of another human's gut. Even with rubber gloves on. Who'd want to do that? But surgeons get over it.

Only the individual can decide what level of risk she can tolerate and what level of freedom she's willing to sacrifice for the sake of safety.

Celebrity stalkers also are not necessarily fixated on one person as the public thinks. Rather, they tend to switch targets, going from, say, an athlete to an actor to a politician.

Counter to the public's thinking, the celebrities who attract the largest number of stalkers - and typically it's not "if" a celebrity has a stalker, it's "how many" - are neither the most glamorous nor obnoxious, but rather the ones who seem the sweetest and most wholesome. They appear approachable.

One of the biggest mistakes celebrities make is being overly friendly. They allow photo shoots in their homes, even their bedrooms and bathrooms; they send fans autographed pictures. All that serves to support viewers with a delusional relationship with the celebrity.

Psychiatrists are usually very well imbued with the clinical role, where helping the sick person is the goal. And that's quite incompatible with the truthseeking role. That's probably true of the other fields, too, but maybe more so of the personalities that gravitate toward psychiatry. They tend to care about people and wish to be helpful.

Our job should be like any other forensic scientist's - we should be truth seekers who are not partisan, who do not have any interest in the outcome, who call it as we see it no matter the consequences. But it seems a lot easier for chemists and anthropologists and pathologists to take that neutral role than it does for psychiatrists.