Before detaining anyone, you must establish Shoplifting Probable Cause. To establish a solid base for probable cause and prevent false arrest claims, there are six universally accepted steps that a merchant should follow before deciding to stop someone suspected of shoplifting:
You must see the shoplifter approach your merchandise
You must see the shoplifter select your merchandise
You must see the shoplifter conceal or carry away or convert your merchandise
You must maintain continuous observation the shoplifter
You must see the shoplifter fail to pay for the merchandise
You must approach the shoplifter outside of the store
A security guard can NOT just walk up to you and detain you... sorry.