Television shows like "Dexter" and "The Following" have given us a terrifying glimpse into the criminal mind of serial killers. We often catch ourselves asking, “Why do they kill?” “How do they pick their victims?” and “Why can’t they control their impulse to kill?” To answer these questions, Best Counseling Degrees has developed “The Brain of A Serial Killer” infographic to explore the genetics, brain patterns, and childhood traumas that make up this profile.

Dr. Helen Morrison, a Chicago-based forensic psychiatrist, has studied and interviewed 135 serial killers. She has found shocking similarities, and believes a chromosome abnormality is a likely trigger. This chromosome abnormality begins to show itself during puberty, especially in men who display their homicidal tendencies. Brain scans show they never develop a sense of attachment and belonging to the world, meaning they don't empathize with their victims, which allows them to kill them.

Neuroscientist Jim Fallon has studied the brains of psychopaths for over 20 years, and stumbled upon a shocking discovery in his research — he has the same low orbital cortex activity as a serial killer. This is the area that is believed to be involved with ethical behavior, more decision making, and impulse control. Low activity in this region means there's less normal suppression of behaviors, including rage, violence, eating, sex, and drinking.

"People with low orbital cortex activity are either free-wheeling types or sociopaths," Fallon said.

When it comes to childhood, serial killers are more likely to have experienced child abuse than society in general. In a study of 50 serial killers, researchers found about 70 percent experience some maltreatment and 50 percent go through psychological abuse growing up. Fallon's research has led him to believe childhood experience could make all the difference when it comes to the making of a serial killer.

Overall, the profile of a serial killer is a person who murders three or more people in at least three separate events with a cooling period between hits. They generally kill during a cycle when they're feeling stress, and feel temporarily relieved after they commit the homicide. The motivations of serial killers vary, but they often fall into these four categories: Obtaining money, experiencing the thrill, a sense of power, and a desire to rid the world of evildoers.

View the infographic below to learn more about the making of a serial killer and the prevalence of homicides around the world.