how to manage a super I dont trust

[Michael C.]

I own a two buildings on the same street for a total of 25 units.    My super is a very local person who lives on the street and grew up there.  His duties include taking out garbage, cleaning,  readying apartments as they turn, and other light property maintenance requests.  He's very local and knows the neighbors, the police, the garbage folks, the local drunks, and other various local labor.

I don't trust him and have caught him skimming off the top on various costs.   The only access to my money that he has is an account at the local hardware store.

He would be very difficult to replace given that I only pay him $20 per door per month as an on-going fee in addition to 'extras' (like $100 to turn a unit).

Does anyone have any tips on how to keep him on a short leash?