Profiling is a technique used in law enforcement to help narrow the field of potential criminal suspects. Investigators compile a list of characteristics (a "profile") likely to be descriptive of a crime's perpetrator, and then alter the focus of an investigation accordingly. A simple example of profiling would be airport security personnel looking for nervous individuals wearing bulky clothes and subjecting them to more thorough searches, since people who carry dangerous devices are more likely to fit that description. However, profiling can be extended to include complex information about behaviors, tendencies, and psychological characteristics in addition to physical identifiers.
- Brent Turvey defines criminal profiling as a careful examination of physical evidence, victimology and all known facts of the crime to infer offender characteristics using the scientific method. 
Experts in psychology and psychiatry are occasionally called upon to generate mental profiles of criminals. Such profiles are usually reserved for high-profile cases, repeat offenders, or particularly heinous offenses, as in cases involving serial killers.
For a more detailed treatment, see Racial profiling.
Profiling may be used to identify liberals by their characteristics. For instance, someone who actively engages in deceit, questionable science, absurdities, hysteria, dubious methodology, logic, and embraces the values of Hollywood and academia is overwhelmingly likely to be liberal.