I'm sorry to hear. There is a reason I always carry my wallet in my front pocket when in crowded areas... and I always do the "3 tap" every so often. (Wallet, Cellphone, Keys, I tap the pocket to make sure they are all there)
Always have eyes on the back of my head too... Then again I grew up in Delco which is right outside Philly, that might have something to do with this conditioning... lol
I hope they catch the bastard