Early civilizations used fingerprinting to mark criminals to show who they were. Thieves were deprived of the hand that was used to commit the crime, and ancient Romans used tattooing to mark soldiers to prevent desertion from their ranks. Before the 1800s, law enforcement officers with visual memory visually identified previously arrested offenders. Photography has eased the burden on memory, but has not solved the problem of identifying criminals, because personal appearances change. Alphonse Bertillon, a French anthropologist, designed a system for measuring and recording the dimensions of certain body parts. These measurements were used to create a theoretical formula that was applicable to a single person and would not change over the course of their adult life. The Bertillon system was used for thirty years, the measurements were close enough to identify a person's physical appearance but it could not be used to identify a single person due to physical similarities between people. The comparison of fingerprints made it possible to quickly and correctly identify each person. A footprint is an “invisible” impression left by friction ridges on the human finger, palm and feet. Friction ridges are raised areas on the skin that are made up of one or more ridges connected together. The use of fingerprints as personal identification dates back to the 20th century, the process involves comparing two or more prints to determine whether or not the prints come from the same individual. An international fingerprint record is made with black ink rolled onto a contrasting background, usually a white card. Today, they can be recorded digitally using live scanning. There are three different types of prints that can be left at a crime scene. Latent prints are...... middle of paper...... oker will fluoresce while non-smokers' fingerprint will remain dark. This process is tested with prints from heavy coffee drinkers, cannabis smokers and even various other drugs. The United States FBI maintains a fingerprint identification system and database and called the Integrated Automated Fingerprint Identification System, or IAFIS, which contains criminal fingerprint records. of more than 51 million criminals and 1.5 million civil records. The validity of the fingerprint evidence has been contested by academics, judges and the media. Although fingerprint identification was an improvement over previous anthropometric methods, the subjective nature of the matching, despite the low error rate, had made the practice controversial. Some criticism is now accepted by leaders in the forensic community, prompting improvements in training and procedures..