Overwhelmingly, killer and victim are of the same sex, race, and age, and they also tend to have similar past criminal involvements - most have been arrested for other offenses. Few homicides involve prior planning. Offenders commit a wide variety of criminal acts, with no strong inclination to pursue a specific criminal act or a pattern of criminal acts to the exclusion of others. People seldom work at crime. Criminal acts involve short-range choices, that they tend to occur on the spur of the moment.
Most criminal actions are brief in duration.
The rewards are small, and fleeting. They are also immediate. Most crimes are easy to commit and very simple in design. Most criminal acts are exciting. Because of their genetic makeup, born criminals could not restrain their violent and animalistic urges.