Bicycle detail

Left in locked custodial closet on Sunday Jane 10th in early afternoon. I am supposedly the only resident in my building who has access to this closet aside from the housekeeper. I usually also use my bike lock to secure the bike in question to another bike. The other bike is cable fixed to a cinder block. On the day in question, however, because of the weather, my bike lock was frozen and I was not able to use it to secure my bike with the bike lock. As usual though, I locked the door behind me. Supposedly no one else has access to this room. When I returned on the morning of the 12th (approx 8am), the door was open and the light had been turned on. I highly suspect one of the residents was involved, or even more likely, one of the staff who works for my property management company.