Different strokes for different folks. I'd suggest a different approach.  

For an organization like OP which experienced funds disappearing from its petty cash, and from its bank deposits what more signals do we need that an internal auditor would be quite appropriate.

 A lawyer on retainer should be all that OP needs.  Lets bring down costs, instead of adding an internal attorney, at the high cost level only recently reached.  I'd suggest redeploying  funds from those oversized, high outside attorney costs,  plus the former HR director costs. ---- Likely could get it done for half of those bucks, with the combination of attorney on retainer, plus an internal auditor. 

You'll recall that OP had an HR gentleman with 40 yrs experience, and pushed him out over a tiff with Trendic.  His pay rate rate was much more reasonable than attorney costs.  Yet he brought  labor relations legal background to the table.  A lower cost idea to again be reconsidered.

Your suggestion for inside counsel would likely cost about equal to the oversized, high costs we've recently been paying.  Seems OP would be building in the increased costs, into all future years.  Not the best idea, for fiscal conservatism.

 OPA is not BG&E.  One internal auditor would be sufficient for OP. Perhaps even a part time position.  Likely that virtually every hotel in OC has a night auditor on staff -- some even with two.  And some have security forces, yet smaller than OP's police dept.  Sizes of needs will vary.

PS  No need for BGE style of having an Auditing Dept, Payroll Dept, Finance Dept, Accounting Dept, etc  (you get the analogy without more elaboration).  No need here for staffing separate Depts and multiple staff positions.  Sizes of needs will vary.

Tom