I am wondering what forensic techniques anyone has used to investigate a point of sales system for the presence/use of "zapper"/automated sales suppression software; I am a Tax investigator who does computer forensics for a state Tax Department and have an interest in developing procedures for detecting automated sales suppression software, and recovering deleted sales information from POS computers and electronic cash registers. I have heard that Quebec, New York and Detroit have done investigations in this area, but I don't have any contacts in those cities.
Not sure who you want contact info for. Detroit, New York, Quebec, doesn't specify a private organization, State, Federal, Local, LE, etc. It's just saying that Detroit, New York, and Quebec have all done investigations on this.
If you could provide more information, I'm sure someone could point you in the right direction.
I was involved in a few of these for the CRA before I retired. PM me.