As a forensic psychologist, I've been asked more than once how common it is to feel like killing someone. Most of can relate to the white-hot rage that so often accompanies these thoughts, especially during a painful relationship breakup or after a public humiliation. There is such a sense of powerlessness in those situations; fantasizing about doing away with the person who caused it is certainly one way to psychologically feel back in control. In fact, research suggests that the vast majority of adult men admit to having had at least one homicidal thought and women, although to a slightly lower degree, aren't far behind. Sixty percent of teen boys also acknowledge at least one murderous fantasy, joined by about a third of teen girls. These homicidal thoughts tended to be short-lived and directly related to a dispute; once the person cooled down, the murderous thoughts disappeared.
Here's where it gets more complicated. A 2017 study in the American Journal of Criminal Justice also found that certain kinds of homicidal fantasies are not only out of the ordinary, but they seem to be directly linked to a variety of serious crimes. These researchers looked at the backgrounds of a variety of criminal offenders to see what percentage had a history of serious homicidal ideation; 88 percent did not. The 12 percent who did, however, were the "worst of the worst;" they were arrested earlier, committed more crimes, and were responsible for the majority of the violent offenses. We've long known that 5 to 10% of offenders commit 50% of all crimes and 60 to 100 percent of the most severe ones. Now we know they also begin thinking about murder sooner.
So how do we make sense of the fact that most of us have brief homicidal urges and never act on them while the most serious offenders have homicidal thoughts and do? The difference between these two groups seems to be in the details. These homicidal thoughts tended to start in childhood and progressed from fleeting ideas to how they might be carried out and what the consequences might be. They also tended to be an extension of a generally angry view of the world in which people are seen as aggressive and untrustworthy; with this worldview, violence - even homicide - can be rationalized.
So where is the line that separates "normal" homicidal fantasies from prophecies of harm? While most homicidal thoughts don't usually mean a person will kill, they do mean something - unresolved anger, unhealed pain, a way to feel more in control, a cry for help. For anyone who experiences frequent or persistent thoughts of hurting someone else, getting help can be the first step toward emotional freedom. And for those who worry that someone they care about is a walking time bomb, speaking up may save two lives - the intended target and the person you care about.
