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 a match, varies from examiner to examiner and from laboratory to laboratory. The decision process, unfortunately, is entirely subjective to the individual running the tests and there is no way to ensure that the examiner will not be susceptible to observer bias. In 2004, after the Madrid train bombings, there were partial fingerprints identified from the bags of the explosives that had been left at the station. After careful consideration, it was determined by the FBI that the fingerprints left on the bag had matched to an individual in Portland, Oregon named Brandon Mayfield. This case, however, went on to change the entire outlook of fingerprint identification within the FBI, as it was later determined that Brandon Mayfield had been wrongly convicted of being an accomplice to the bombings in Madrid. Because of this, the FBI is no longer able to testify that fingerprint identification is a 100% accurate technique for profiling, and should therefore be considered very carefully by anyone who uses it.