So, the central plot of my story revolves around two characters with special powers, one who's a serial killer murdering people for initially unknown reasons, and the protagonist, who's trying to catch and stop him because he knows only somebody like him could be pulling off these murders but for masquerade purposes regarding the existence of people like him he can't go to the police about it. What the protagonist doesn't realize until later is that the serial killer is actually trying to hunt him down. During the initial anonymous "meeting" between all 24 of these supers, another one of the supers let slip a tiny bit of information about the protagonist's location that it turns out the serial killer super has been using to try and track him down. Upon brainstorming what this information could be, I initially thought it was the third one casually mentioning the restaurant the protagonist was in, a restaurant that both the third member and the protagonist thought was a chain and thus useless information. But it later turns out there's only one of them, and that the third one just gave everyone who cared to connect the dots the protagonist's exact location on the day and time of the meeting. I was thinking that the serial killer super would then head to that restaurant and determine who exactly had been at the restaurant on that day and during the hour of the meeting, and then hunt down every male customer that hour one by one. Now this sounded good at first, but it later occurred to me that I have no idea what kinds of records restaurants keep of their orders, and that the only ones that would have a name attached to them would probably be the credit card users. Am I mistaken? Is there anything I should know about restaurants that would let me salvage this? Right now I'm debating what kind of feature I could add to this restaurant that would make it feasible for the killer to get a list of names (or at least faces) of the people who ate there at a certain time and day without drawing too much attention to the fact so that it's believable that the protagonist wouldn't suspect the killer is after him until he discovers that the place he ate at wasn't a chain.