The Doctors welcome Dr. James Fallon, a neuroscientist and professor of psychiatry and human behavior at The University of Irvine, to discuss how the brain of a killer may differ from other brains.

Dr. Fallon, who has studied thousands of brain scans for 30 years, says he has seen a pattern in the scans of people who have taken other people's lives. He explains that in scans he has viewed of killers, that it appears parts of their brain have been "turned off." He goes on to explain that in one case, a person was shown pictures of "awful things" and Dr. Fallon says he had no brain response to the horrifying images.

Watch: The Shocking Results of Studying Serial Killers’ Brains

He tells The Doctors in many instances, people who kill or commit other crimes like rape do not think what they are doing is wrong. He also notes in the brain of a killer there is a lack of balance between the various parts of the brain, which helps most people to determine the difference between what is wrong and right. He says that in the mind of a killer, it is possible for that person to look at a bus of children on fire in the same way they would look at a photo of flowers. 

During his years of research, Dr. Fallon says he saw a common development trait among killers.

Watch: Is Your Kid a Psychopath?

"Every psychopath that we looked at... everyone one for them, was either abandoned in the first 2 or 3 years of life or they were abused somehow. Every one, every killer I looked at," he explains.

Check out the video below to find out the shocking discovery Dr. Fallon made when he examined his own brain scan.