John Hamilton, an engineer on the faculty of the Mechanical Engineering department at the University of Arkansas has posted on his site a primer on evidentiary photography using film.
(His “Hazard Evaluation” article in Plant Engineering, written with John S. Morse, is also an excellent primer, a starting point for litigators, investigators, or others new to the consideration of industrial, occupational) and/or public health risk).
There are many virtues of using digital rather than film, cost not least among them. But, things being what they are – one virtue of handing over, say, a contact sheet and prints, and permitting inspection of negatives, is going to tend to reduce the temptation to allege photo manipulation. If you’re thinking about shooting in film, Professor Hamilton’s primer is worth having in hand as you proceed.
For the entirely obsessive-compulsive – a class which includes nearly all attorneys some of the time, and some attorneys all of the time – shooting digital and film in parallel might be the safest course, if not the most cost effective.
As the writer of the article I would like to thank Mr Soroko for linking to it. and I would also like to point out that EVERYTHING in that article of a technical nature can be applied to digital photography. I wrote that article almost 10 years ago and I have myself since converted to digital.