In the United States, a majority of known and reported serial killers are Caucasian males in their 20s and 30s. Though white males comprise the majority of reported serial killer cases, according to the FBI they are not statistically more likely to be serial killers. Approximately 40 percent of reported and documented serial killers between 1900 and 2010 were African American.
A serial killer is defined as someone who has killed three or more people over an extended period, with cool-down time between the murders. According to the FBI, serial murders account for less than 1 percent of the total murders committed in a single year. Female serial killers comprise approximately 15 percent of American serial killers, a statistic based on all known American serial killers. Female serial killers are more often classified as "comfort killers," a type of serial killer who kills for material gain, than male serial killers. Approximately 76 percent of all documented serial killers in the 20th century were American.
Notable American serial killers include Jeffery Dahmer, who was convicted of murdering 15 men, Ted Bundy, who was executed in 1989, John Wayne Gacy, executed in 1994, Gary Ridgway, a serial killer from Washington State, and Tommy Lynn Sells, a serial killer from Texas.