Warning Signs That Someone Is Capable of Murder

The article "Psychology and Criminal Profiling," written by Junko Kotake in "Forensic Biology," warns that because there are so many reasons for a person to become a murderer, there are limits to warning signs that someone is capable of murder. Many who display all the signs of a potential murderer never commit a murder. The best that can be done, said Kotake, is to avoid people who display too many of the personality traits of a murderer. (See Reference section.)

Jealousy and Possessiveness

• Someone who is jealous and possessive can be very dangerous, even to the point of murder in cases of job loss, divorce and other upsetting occurrences, according to Jack Levin, professor of sociology and criminology at Northeastern University. Jealous or possessive behavior is not cute, Levin said in an interview in "Newsweek," and it is not a sign that he "loves you so much." Jealous people are often abusers, which is another indication that a person is capable of going too far and committing murder. (See Reference section.)

Impulsive Temper

• A person who doesn't control his rage or anger will soon be -- if he isn't already -- unable to control those emotions. This is a very dangerous person, said Derek Wood, RN, BSN, in "Antisocial Personality Disorder Overview." Wood notes that these people often alternate rage or anger with small expressions of love and approval, which causes an addictive cycle and makes the potential murder victims feel helpless. The potential murderer will exceed one boundary after another until he has no sense of personal boundaries and no concern for his impact on others. (See "Profile of the Sociopath" website in Reference section.)

Juvenile Delinquency

• Criminal profilers often learn that a person who committed murder had a history of juvenile delinquency or other criminal behavior. Often, that person also has a history of academic difficulties or failures, Wood said. Profilers find that along with aberrant behaviors such as cruelty to animals or people, many convicted murderers had problems making friends and keeping friends. These people often get by in life by conning others and taking advantage of them. (See "Profile of the Sociopath" website in Reference section.)

Habitual Liars and Narcissists

• In "The Malignant Personality," Caroline Konrad writes that habitual liars, narcissists and remorselessly vindictive people, when exposed, are potentially very dangerous. These people, she said, can have a false sense of religion, but do not have empathy for others and their social behavior is a facade. They often feel superior to others, and blame others for all their problems or anything bad that happens to them; they take little or no responsibilities for their actions. (See "Profile of the Sociopath" website in Reference section.)