Dollar Tree

I went in dollar tree this morning and I walked in and the cashier spoke "good morning" and I spoke back. The next thing I here is "we have a big backpack in here. She said it real loud like i'm in there to steal. I would never steal nothing. I pay for everything I want. I feel like that's profiling me as a thief because i'm black with a backpack. I've went in there several times with my backpack and has never went through nothing like that. That's very embarrassing. I didn't say anything, I just walked out.