Why is it so hard to catch them? Can't the FTC set up a house sale, and when the buyer presents himself at closing, have him arrested? Eventually the buyer need

Why is it so hard to catch them? Can't the FTC set up a house sale, and when the buyer presents himself at closing, have him arrested? Eventually the buyer needs to be available to close the sale. I suppose it can all be done electronically (I bought property with an electronic closing) but for the demographic they're trying to market from, electronic signatures and document handling may not be easy. Someone will have to meet with them, and there an arrest can be made (for the robocalling).