Cold-blooded killers are individuals who commit murder without any emotion or remorse. The term 'cold-blooded killers' is often used to describe serial killers, as they often lack empathy and have a lack of remorse for their actions. The acronym ASPS stands for 'Antisocial Personality Syndrome, ' which is a mental disorder characterized by a lack of empathy and disregard for the feelings of others. People with this disorder are more likely to become cold-blooded killers.