As others have posted, it is possible that a shelter will confiscate certain belongings. However I have an idea that may help.

Get an amateur radio license (ham ticket) and spend $250 or so on a decont 2M radio, portable antenna, and a couple of batteries. Then, you volunteer to work communications at the shelter.

Then, instead of being one of the cattle packed in there, you can get some more private accomidations, and are always clued into what is going on. And, since you have to carry all of this gear, they are a LOT less likely to go poking around in your stuff. It worked for me in Central Florida about a year ago.