A killer is a person who kills someone or something. The word is also used as a synonym for a murderer or any violent crime. People who commit crimes of this nature are called serial killers. It is thought that the ability to commit multiple murders is based on a combination of factors. These may include a genetic predisposition, psychological makeup and specific events at a critical point in the person’s social development. It is believed that a rare confluence of these factors occurs in some individuals and creates the conditions that result in their serial murder.

The most well-known serial killers were those involved in organized crime. However, there have been several people who committed serial killings for no particular reason at all. One example of this is the U.S. serial killer known as the Iceman who was able to kill 100-250 people before being caught. Other examples of serial killings are those committed by contract killers or for personal gain such as money, power and status.

Most serial killers operate within a defined geographic area. These areas are often defined by their home, place of employment or the residence of a relative. Some of the more prolific serial killers like Richard Kuklinski who killed in New York and Ohio operated beyond their comfort zones to achieve more victims. This type of killer is often referred to as a traveling serial killer. Itinerant individuals who travel for their work such as truck drivers and military personnel are also considered travelling serial killers.

Many of the same reasons that lead some people to become serial killers can be applied to other types of crimes such as kidnapping and robbery. The motivation for these crimes is usually a desire to acquire a specific resource or money, such as power and status, which may be gained through theft, fraud or extortion. For example, the Medici family of Renaissance Italy or Landru, the “bluebeard” of World War I were motivated by greed and a desire for power and wealth.

It is widely believed that once a person begins a pattern of serial murder, they cannot stop. In some instances this is true, but there are also cases where offenders will stop killing after a certain number of victims. Some of these stops occur because the offender becomes too occupied with family activities, sexual substitution or other distractions. Other times they are stopped by law enforcement or other factors.

Movies centered around serial killing have been a reliable box-office draw for over a century and range from the critically acclaimed to the formulaic. The best movies about serial killers, however, go beyond delivering transgressive shocks to question the conditions that make these individuals tick. Below is a list of the most notable and disturbing films that do just this. Some of these films are even regarded as classics. Some of them are so disturbing that they can leave the viewer unnerved for a long time.