Latent fingerprints are usually left behind by accident, because a careless criminal did not realize that his or her hands might leave a mark. Sometimes, fingerprints are made from substances other than sweat, such as blood, other body fluids, or paint. In this case, they are called patent fingerprints. Part of the analysis performed on fingerprints includes a determination of what the print was made from, as this may provide additional evidence about the criminal or the crime.