老貓 help me!!Shoplifting without being caught!

Help! 單身老貓 and other law experts!
Last friday i went into a furniture store from the front door, then i found a chair at the back door. After i negotiated the price of the chair, the staff left. I took the chair away at the back door without being found. The chair is worth $30. I didn't see any video camera head inside and outside the back door. I am not sure whether there is video camera head inside and outside the front door, but i think there should not be any because furnitures are too big to be shoplifted. Yesterday I knew that they found the chair lost because the back door was closed and the is a sign which says: “use the front door”.
Because I was seen by the staff when negotiating the price, and I am not sure whether my picture was recorded by the store, if they reported the case to the police, will I be caught?
I already filed 485 and received my work Permit. I had my finger prints pressed and my face pictured a week ago at the Immigration office. Should I return the chair to the store? If I return the chair, will the staff withdraw the police report? What if I am caught if I return the chair? What if I return the chair without being found?
Thanks a million!!!
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