I guess if you live in the area it kind of makes more sense. So Tower Hamlets (because I know it) has around 100 serious crimes per 1000 inhabitants each year. One in 10 of the EE characters is probably capable if not coupable of duchess stuff at some time!
My DD was friends with Dirty Den's real son who was ginger. (Useless information, I know!)
Being quizzed by chemist's assistant in Boots.