Visualization of partial bloody fingerprints on nonporous substrates using columnar thin films

A partial bloody fingerprint has both a bloody part and a non-bloody part, each of which should be developed for visualization. Traditional techniques employ developmental cascades, whereby a sequence of development techniques is used to develop both parts of the fingerprint. As a one-step alternative, a columnar thin film (CTF) was deposited on each of several partial bloody prints from one finger of one donor on several nonporous substrates. A split-print methodology was adopted to compare the CTF technique to several traditional development techniques, using both objective computer-based grading and subjective grading by a lay examiner. CTF development was found to be superior to development with the traditional techniques employed in this study for partial bloody fingerprints on brass, anodized aluminum, hard plastics, and clear sandwich bags. Unlike the traditional techniques used, the CTF technique was able to develop the entire fingerprint on many of these substrates.