Physical evidence is useful (1) to determine how a crime was committed, (2) to connect a suspect with the crime or identify the criminal, or (3) to clear an innocent person. The use of fingerprints is shown to be crucial in identifying an offender, and footprints are reported to have been useful in establishing the line of entry and exit of the perpetrator in a murder case, as well as his identity. Hair found under the fingernails of a murder victim is shown to have helped in establishing the fact of a struggle between the victim and the murderer, as well as a physical attribute of the murderer. The matching of a found pellet with the type of gun used in a killing is reported to have established the place of the crime's commission, and bark under the fingernails of a man found hanging from a tree helped establish that his death was a suicide. Furthermore, a comparison of a forged signature on a hospital check with handwriting samples of hospital staff members established a staff member as the forger. The use of physical evidence to trace offenders in hit-and-run traffic accidents is also illustrated. No references are cited.