NCJ Number
195826
Journal
Journal of Forensic Identification Volume: 52 Issue: 4 Dated: July/August 2002 Pages: 409-419
Date Published
2002
Length
11 pages
Annotation
This paper describes a case in which strips of 35 mm negatives alleged to be second or third generation copies were proven to be original negatives from a specific camera based on a comparison of frame edge defects.
Abstract
The criminalist is occasionally confronted with the challenge of determining whether a given film negative was exposed in a particular camera. This information may be necessary to establish the ownership of a stolen camera, to associate a camera with negatives of questioned origin, or to determine whether two or more film negatives were exposed in the same camera. In the case profiled in this paper, the defendant, in a recent criminal appeal, claimed that photographic negatives of a questioned fingermark, used by police in 1983 to obtain a conviction, were not original negatives, but were second or third generation copies. The defendant alleged that the police substituted poor copies of the original negatives so that fine detail would not be present to indicate that the fingermark in question was a forgery. The questioned fingermark had been developed on the back of a stolen bank check in Perth, Western Australia. The Forensic Services' laboratory of the Australian Federal Police was asked to examine the negatives in question and determine their origin. In addition to these negatives, the laboratory had access to a large quantity of negatives known to have been exposed in Canberra during the period 1981 to 1983 using the same Olympus OM-2 camera that photographed the questioned fingermark in July 1982. The actual camera itself could not be located. The examination and comparison of photographic negatives was conducted by using a Leitz comparison microscope in the transmission mode at eyepiece magnifications up to approximately 30X. Images were captured by using a high resolution CCD camera, and hard copies were produced on a Sony Mavigraph video printer. The result confirmed that the majority of frame edge marking observed in these negatives was not due to permanent defects that could be related to the manufacture of the camera (i.e., class characteristics). Rather, the markings were due to the random arrangement of dust and other particles on the inside surfaces of the camera (i.e., individual characteristics). Thus, any negative that had edge defects that matched all of those observed in the July 1982 film could only have been taken in the same camera at some time between December 1981 and October 1982. 12 figures and 2 references