FYI, we don't "all" have those "forms".... An officer will likely take the SD card and include it in the evidence collected at the scene, and submit it in the agency report.... yes, I am forced to work for an alphabet agency for my day job..
chain of custody forms are only good for the officer who is investigating the incident or for an investigating department. a chain of custody form provided by a civilian will get tossed everytime. So,,, hint.. if you have a way to back it up and provide an SD or otherwise to the scene collector, this covers your butt twice....