We found an expert with a PhD in biochemistry and 20 years of experience working with fingerprints. In fact, he was an expert in the biochemical composition of deposited fingerprints. His experience included working in forensics for a large metropolitan area where he led the fingerprint lab. Through his work identifying DNA in deposited fingerprints, he developed expert knowledge in the biological components of deposited fingerprints. Additionally, he was highly knowledgeable in the enzymes used on deposited fingerprints thus eliminating the need for a second expert in enzyme immobilization. Finally, he had served as a testifying expert in nine cases most of which involved biochemistry and fingerprints.