Dear Employer,
I thoroughly studied your job description, and it appears to me that you mostly worried about the propriety of the software - and that means that you do not want the person developing the code understand what they are developing and you do not want to expose the real data.
Thus, the Cincinnati proximity requirement.
As there might not be enough freelancers in Cincinnati, may I propose a couple of things that might actually satisfy your requirement and bring up potential pitfalls that you are not thinking now about.
Separating subject matter from implementation usually done by letting an architect define the abstract algorithm (sequence of operations) and developer develop it.
Data masking is used for hiding real data. Algorithms are checked on artificial data.
Employing a company instead of individual allows you to sign NDAs.
After deployment, the code might be deleted. A lot of things might be encrypted, including both code and data.
However, after the deployment I would suggest you think about supporting your application - every so and then Microsoft and other vendors change their tools and languages and you also need someone to deal with the backups and flowless operations - and if you hide the code, it might bite you at the end.
Thus, if considering all of the above might have changed your perspective on hiring exclusively local candidate, I would like to have a talk.
The bid is preliminary, and might change with better specification.
Virginia