ST. PETERSBURG, Fla. -- “There’s no physical description of a serial killer,” says Marjorie Sanfilippo, Professor of Psychology at Eckerd College.

But Sanfilippo says there is nothing you can really detect when it comes to the mind of a serial killer.

“The things an average person picks up on, probably not,” says Sanfilippo. “They tend to be manipulative, cold, and callous. They lack empathy. Psychopaths tend to be psychopaths at a very young age. The sort of behaviors they engage in as a child, we called a triad—fire setting, bed wetting and hurting animals.”

Sanfilippo says there is no cure when it comes to curing these traits.

“For the most part, they’re very resistant to change. They grow into adults who don’t see anything wrong with what they are doing.”

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