The use of a wanted poster dates back to the days of the Old West in the United States when bank robbers were commonly the subject of a wanted poster. When a law enforcement agency wishes to apprehend an individual who is alleged to have committed a crime, one method they use is a wanted poster. Information contained on a wanted poster may include a photograph of the individual or composite drawing, the crime for which the person is wanted, and identifying characteristics such as height, weight, and scars or tattoos.

The idea behind the use of a wanted poster is to alert the public to the fact that law enforcement agencies are looking for the person in the poster. Traditionally, wanted posters have been posted in public locations, such as police stations, post offices, and government offices. Along with information regarding the suspect, a wanted poster usually includes contact information for the law enforcement agency that is looking for the suspect in the event a citizen has information. Although law enforcement agencies are by far the biggest users of wanted posters, other companies, such as armored car companies, have been known to use them as well when they have been the victim of a crime.

Information included on a wanted poster may be specific or general in nature, depending on how much information law enforcement agencies have on the suspect. In some cases, the poster will have more than one photograph if the suspect has been arrested before and booking photographs are available. In other cases, a snapshot from a video surveillance camera may be included or a composite sketch if no photograph is available.

If the name of the suspect is known, the name will be posted on the poster along with any known aliases. Detailed information regarding the height, weight, and hair and eye color will also be on the poster, if available. Identifying marks such as tattoos, scars, or physical imperfections may also be included.

Wanted posters have traditionally been printed on paper and placed in well trafficked public locations. In 2007, however, the US Federal Bureau of Investigation (FBI) began using electronic billboards to expand the use of wanted posters. The benefit to using electronic billboards is that a picture of a suspect may be broadcast virtually minutes after the commission of a crime, which markedly increases the chance that he or she will be apprehended.