Democrat Campaign Manager's Cat Murdered 'Liberal' written on dead cat

One of the known warning signs of certain psychopathologies, including antisocial personality disorder, also known as psychopathic personality disorder, is a history of torturing pets and small animals, a behavior known as zoosadism. According to the New York Times, "he FBI has found that a history of cruelty to animals is one of the traits that regularly appears in its computer records of serial rapists and murderers, and the standard diagnostic and treatment manual for psychiatric and emotional disorders lists cruelty to animals a diagnostic criterion for conduct disorders. "A survey of psychiatric patients who had repeatedly tortured dogs and cats found all of them had high levels of aggression toward people as well, including one patient who had murdered a young boy." Robert K. Ressler, an agent with the Federal Bureau of Investigation's behavioral sciences unit, studied serial killers and noted,"Murderers like this (Jeffrey Dahmer) very often start out by killing and torturing animals as kids."

Cruelty to animals is one of the three components of the Macdonald triad, indicators of violent antisocial behavior in children and adolescents. According to the studies used to form this model, cruelty to animals is a common (but not universal) behavior in children and adolescents who grow up to become serial killers and other violent criminals.

It has also been found that children who are cruel to animals have often witnessed or been victims of abuse themselves. In two separate studies cited by the Humane Society of the United States roughly one-third of families suffering from domestic abuse indicated that at least one child had hurt or killed a pet.