In areas with new redesigned pre-clearance areas, the process is a little bit different. After you drop your bags off with the airline after check in, you don't see your bags again until arrival in the US. When you are at the Customs and Immigration Booth, they will scan your boarding pass and an x-ray of your bags comes up on the screen for the officer to review. I have experienced this with pre-clearing in to the US from Winnipeg and Montreal in Canada. I would expect something similar if and when preclearance is setup in SXM.