Why would he NOT want business from, and the presence of, police?? Sounds shady. Is this a drug dealer’s den? Is this restaurant a meeting place for the local Registered Sex Offenders? Is the “chef” processing local stray cats into teriyaki? Is their kitchen consistently violating health and sanitary standards and they want to hide it from the enforcement authorities? Do their cooks and waiters not wash their hands when they use the bathrooms? Do they overcharge customers on the condom machines in the men’s room?
Well, it IS a chinese restaurant. Third world sanitary conditions are just part of the ambience of those places.
Enough complaints about sanitation can make their life even more difficult. Spray painting "why are all the dogs and cats disappearing in this neighborhood?" on the outside of the building would be appropriately droll, I think.