File systems, thumb drives, and DVRs

I get a lot of help requests from LE employees trying to retrieve DME at crime scenes. Some of them work like this:

Officer: "I'm standing in front of the DVR. I'm trying to back-up the data but the DVR won't see my thumb drive. What am I doing wrong?"
Me: "What file system are you using on your thumb drive?"
Officer: "What do you mean?"

Officer: "I'm standing in front of the DVR. I'm trying to back-up the data and the DVR is asking if I want to format by USB stick. Should I click OK?"
Me: "Is the drive empty?
Officer: "I've got a bunch of case files on it."
Me: "Click cancel and get another drive."

I keep a bag of thumb drives of various sizes and formats. Some older systems won't accept a thumb drive with a capacity larger than 2gb formatted as FAT. Others won't accept anything larger than 4gb. However, 4gb is a nice size to carry as you'll want to move the files to WORM discs when you create the master evidentiary copy. Most people have DVD readers, so this bit of pre-file management will help you keep organized.

So, don't throw away those old jump drives. You may need them some day.