A poster distributed by police to warn the public about a criminal who is wanted for arrest. A wanted poster usually has the word "WANTED" at top, and the fugitive's name and picture on bottom. Sometimes a bounty is included.
In earlier times (or fictional settings), wanted posters would sometimes also read "wanted alive or dead", making the wanted criminal an outlaw in the literal sense (i.e. a person from whom the protection of the law was withdrawn and who could be killed without official repercussions by anyone).