Witnessing identification: Latent fingerprinting evidence and expert knowledge

The technique of latent fingerprint identification enjoys a remarkable degr ee of credibility, even in the adversarial climate of the Anglo-American cr iminal trial. Latent fingerprint examiners (LFPEs) are treated with a high degree of deference in court proceedings. I trace this to the historical pr ocess by which latent fingerprint examiners constructed rules of method and practice which allowed them to present fingerprint identifications as matt ers of fact. First, LFPEs maintained professional jurisdiction over the int erpretation of fingerprint evidence, even while suggesting that the evidenc e was 'speaking for itself'. Second, LFPEs devised rules of method and prac tice which encouraged unanimity and consistency within the profession. Fina lly, LFPEs managed cases of error by attributing failure to individual prac titioners rather than to the method. I conclude that LFPEs offer a highly i diosyncratic model of scientific evidence, one which new forensic identific ation techniques, such as DNA typing, will be able to emulate only with dif ficulty.