The management might have preferred the store closure to having the bakery department marked off with crime scene tape in full view of any customers. And the cops probably appreciated not having a bunch of lookie-loos staring at them across the tape. Plus I imagine that the dead woman's mother isn't the only employee dealing with shock/mental health issues because of this. They may not have been able to get enough staff willing to come in to reopen the store immediately.

(TL;DR: There may well be something ugly going on here, but I don't think the store being closed is enough evidence to prove that on its own.)