When I used to own my own store, I was never afraid of stray bullets or other dangers when I was there alone at night. It was in a completely safe area, and I was friendly with the surrounding businesses and residents. It seemed very protected, and I'm thankful for that.
Unfortunately, some businesses have no choice but to invest in kevlar sheets to protect their employees from gun violence. From what I've read, kevlar is a popular material used to turn everyday items into bullet-proof ones. I'm pretty sure that's what my mom's police officer friend said his vest was made out of, so I would imagine it to be pretty sturdy and protective. Even so, I'm not sure something as simple as a kevlar sheet could make me feel secure in a truly dangerous area. I give a lot of credit to business people who aren't afraid to stand their ground in less desireable neighborhoods.