"Victim selection by serial murderers is often very specific" says expert

Forensic psychologist Kris Mohandie explains what drives serial killers like Michael Gargiulo

Inside the mind of the Hollywood Ripper

Last Updated Sep 16, 2019 4:12 PM EDT

Kris Mohandie is a clinical, police and forensic psychologist with more than 30 years of experience in the psychology of violence. He has conducted extensive interviews of violent offenders, including stalkers, hostage takers, and serial murderers. He is a "48 Hours" consultant and has studied the case of Michael Gargiulo, dubbed the Hollywood Ripper.

"48 Hours" asked Mohandie what it says about Gargiulo that he chose victims who lived nearby and what could have motivated the attacks on Tricia Pacaccio, Ashley Ellerin, Maria Bruno and Michelle Murphy. Mohandie says "victim selection by serial murderers is often very specific," and typically serial murderers will have a preferred victim type based on age, appearance or location.

Mohandie didn't interview Gargiulo, but he reviewed the reports of the defense expert who did. In reviewing the specifics of the four attacks Gargiulo was charged with, Mohandie says "taking a couple commonalities from this case, the repeated stabbings, the offender being from the same neighborhood or vicinity, the fact that there is little or no DNA evidence, what you're speaking to here is a guy who is willing to take extraordinary risks. Because he's attacking, in his neighborhood. But he's sophisticated enough to be able to avoid leaving DNA behind. So he's bright. And the use of a knife, a personal weapon that is repeatedly used suggests hostility towards women, that there is a detachment from the pain and suffering."

In the video clip above, Mohandie also explains what usually causes the escalation from stalking to murder, and what a serial killer is thinking in the time between attacks.

Kris Mohandie's new book,"Evil Thoughts: Wicked Deeds, will be released on November 15. It is published by Post Hill Press and distributed by Simon & Schuster, a division of CBS.