Optimized Development of Sebaceous Fingermarks on Nonporous Substrates with Conformal Columnar Thin Films

A form of physical vapor deposition, called the conformal-evaporated-film-by-rotation (CEFR) method, was optimized for the conformal deposition of columnar thin films (CTFs) on sebaceous fingermarks. Relying on the surface topology of the fingermark, the CTF development technique is different from traditional development techniques. After the optimization of the development conditions, the CTF development technique was found to be superior to traditional development methods on several nonporous substrates: the smooth side of Scotch^® Multitask, Gorilla^®, and Scotch^® Duct tapes; clear and black soft plastics; stained and sealed walnut and cherry woods; partial bloody fingermarks on stainless steel; and discharged cartridge casings. It was equally as good as other development techniques on other substrates, but worse on a few. The optimization study is expected to assist in designing a mobile CEFR apparatus capable of on-scene development of fingermarks.