Patrick,

SJC said that, "There should be one standard that is adequate for all pasengers, all of the time." He didn't say that buying a last minute ticket should not result in additional screening. His statement said that people, no matter what the reason, should only ever be subject to the one screening. Your post talked about having a reason to suspect passengers. If you followed SJC's protocol, it wouldn't matter if anyone was suspected. Everyone would only be subject to the basic screening.