negative) error rates. They also vary in terms of features such as image rotation invariance and independence from a reference point (usually, the "core", or center of the fingerprint pattern). The accuracy of the algorithm, print matching speed, robustness to poor image quality, and the characteristics noted above are critical elements of system performance. Fingerprint matching has an enormous computational burden. Some larger AFIS vendors deploy custom hardware while others use software to attain matching speed and throughput. In general, it is desirable to have, at the least, a two-stage search. The first stage will generally make use of global fingerprint characteristics while the second stage is the minutia matcher. In any case, the search systems return results with some numerical measure of the probability of a match (a "score"). In ten-print searching, using a "search threshold" parameter to increase accuracy, there should seldom be more than a single candidate unless there are multiple records from the same candidate in the database. Many systems use a broader search in order to reduce the number of missed identifications, and these searches can return from one to ten possible matches. Latent to tenprint searching will frequently return many (often fifty or more) candidates because of limited and poor quality input data. The confirmation of system-suggested candidates is usually performed by a technician in forensic systems. In recent years, though, "lights-out" or "auto-confirm" algorithms produce "identified" or "non-identified" responses without a human operator looking at the prints, provided the matching score is high enough. "Lights-out" or "auto-confirm" is often used in civil identification systems, and is increasingly used in criminal identification systems as well. Skepticism For many years, the FBI have presented the claim that fingerprint identification is a fully accurate and dependable source for profiling and identification. The belief in this technique was based on the assumption that there are no two fingerprints that are the same and that every person has their own unique pattern. However, there is no scientific evidence or studies that have been done to support this claim. This can also be applied to other forms of forensic identification, such as bite mark analysis — also known as forensic dentistry, which can be seen in a case of Levon Brooks. In terms of fingerprint identification, FBI agents who are responsible for examining the prints to determine the points of similarity in order to tell if they have secured