I think it is completely reasonable to have the staff pay careful attention to shoppers who come in with a bag of some sort. Was it a large bag? Maybe this was a new employee and the manager was letting her know what type of things to watch for to prevent theft. When you come in to a store with a bag or bags, it does look suspicious, as anybody could easily slip merchandise in there as well. Some stores will even make you leave your bags while you are shopping. I know Dollar Tree makes you check any large bags or backpacks you have at the front counter.

Also, it is crazy to think that this happened because you are "African American". Shoplifters come in all colors, and you heard her specifically say it was because you had a bag. When I worked retail, I had my eyes open for everything - I didn't even think about race.

I do agree however that it could have been more discreet.