I was the finger print officer for CSI in Manvel PD.
Keep the bag closed just as found and have wife call police, date and time she found it.
Write everything down you did with bag!
Now if police do not want to finger print it you have to show proof of who had the evidence so make a one up on paper and make people sign for it EVERY time!
As for how you are holding it now place in safe date and time it. ALWAYS date and time with signing it so it will show who had it.
Defence Att would love to attack that, which would show it was out of your "hands" per say.

There are many ways to print and enought has been said.

just my .02 for what it is worth.