Learn about the stories behind 10 extraordinary inventions. In this video, you'll learn about fingerprints.
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John Vogan: Initially, when the crime is committed, the officer who gets the call will first respond to the scene while determine if there is a need for a crime scene technicians to come out and look for fingerprints and other types of evidence. And if they feel they need our CSI people, they respond to the scene of the crime and they search for evidence, recover any fingerprint evidence that they feel is relevant to the investigation. And then, that evidence is delivered to our crime lab appear on the third floor headquarters and depending on what has to be done with different types of evidence it goes to the different forensic specialties in our lab, firearms, the drugs and that sort of things. And the fingerprint evidence, of course comes of dust. So, if we have the name of the suspect, of a passport perpetrator, the first thing we do is to look to see if they have a record with us, that's available for us to make a comparison with the fingerprint evidence. And if the suspect does not have a record, then we will search their fingerprints through our AFIS computer system, the fingerprint evidence and attempt to identify. And this AFIS system is a state wide system and that gives us access to fingerprint cards from all over the state. That is, approximately 1.7 million fingerprint cards in the database at this time, which would be 17 million individual fingerprints. So, we use this computer system to try and identify the crime scene evidence and it's a very accurate system and provides us with hundreds of suspects every year. After we identify the fingerprint evidence from the crime scene, then we get hold of the investigators and the detectives that are responsible for investigating that particular crime if it's a homicide, we contact homicide division, if it's a burglary or stolen car, we contact the neighborhood detective units and they will go out and try and locate the person we've identified and attempt to arrest him if necessary or at least interview him and find out why their fingerprints were to scene in this crime. Not everyone we identify is a perpetrator. Sometimes, they are witnesses, sometimes they are just innocent individuals who may have been arrested years ago for some minor offense and their fingerprints on our database. But, most of the time about 90% of the time, we identify someone who is involved in the commission of a crime either aiding and abetting or actually committing the crime itself. And then, after we have located this person, our detectives decide whether to arrest him or not and the circuit's attorney's office has to decide whether or not to prosecute him. And if they feel the case is strong enough, then they will prosecute the person for the offense, and then as forensic fingerprint experts, we have to go in court and testify as to the identity of the fingerprint evidence from the crime scene and how we linked that particular individual to the crime scene. Just to give you an idea of how this AFIS systems help us. We had fingerprint from burglary and it was partial fingerprint, from a basement window where a young man broke in. We were able through the use of a computer system to identify that fingerprint. The computer itself even said we didn't have much of a chance, but it did find the right person. Just that one partial fingerprint of a basement window helped us that was good for a 300 burglaries in a five month period, which is a lot of homes broken into. The power of the computer, it will do 20 years work in 20 minutes. Then we have markers mark details within the fingerprint itself within the rid structure that we use to identify our fingerprint. and then, on the crime scene print, we mark details on the crime scene print and what the computer does is that it attempts to overlay the markings that we put on the crime scene print with a final print to see if they can find the one that matches exactly in the way that the markings are put on it. Then it sends us a possible match and we