I wonder how much of this is just because who's going to believe some random email that "law enforcement" wants to see my security camera footage? We live in an age where the "IRS" calls every day to inform me that they're going to come arrest me, and I'm supposed to hand over surveillance footage to some random email?
About a year ago someone was murdered near my office. Our office is in a townhouse in a mostly residential neighborhood. Detectives came by in person to ask if we had any surveillance cameras that might have footage they can look at to see if it might have the killer on it. They didn't just send an email.