For those of you who used to know me, this is Heidi Fraser; I just got married and got a new account name, so "Heidi Eldridge" is what you'll see from now on.
I have some questions about ninhydrin. We're going through our Procedures Manual and doing a lot of questioning of how "things have always been done" in an attempt to substantiate WHY we do things the way we do them. We've found that a lot of our written policies seem to have their roots in oral tradition, and we're trying to track down actual research that shows these things are not simply forensic wives' tales. I was hoping some of you could help me out...
Do any of you have citations (or personal empirical knowledge of the reasons) for:
(1) Letting ninhydrin sit for 24 hours after processing to develop before evaluating prints;
(2) Letting ninhydrin sit in the dark while developing.
Or do you even do it this way? I was always told the 24 hour thing was sort of arbitrary and based on the fact that prints can continue to develop for an unknown amount of time, but due to operational needs, a line needs to be drawn somewhere to get casework out the door. Has anyone else heard differently? Anyone know of any studies?
And as far as the dark thing goes -- is it even necessary?