PET scan studies have found that the prefrontal cortex of predatory murderers has less brain activity than does the prefrontal cortex of men who commit "heat of passion" murders.

PET Scan

A medical imaging technique that uses radioactive substances to visualize and measure changes in metabolic processes.

Prefrontal Cortex

The part of the frontal lobes of the brain lying just behind the forehead, involved in complex cognitive behavior, personality expression, decision making, and moderating social behavior.

Predatory Murderers

Individuals who plan and execute murders in a premeditated and unemotional manner, often for personal gain.