Lieutenant,
I'm in the process of building up a video surveillance system for my home and have been lurking here. There are solutions out there for your exact problem. One of them is called StarWitness DVRPro from a company called Signalscape. This technology is VERY popular in the LE and government space.
There are even federal grant programs available such as CTAC, TTP, CETA, etc that may be available to you.
I should disclose that I work for this company, but am not a salesperson. If you are interested in learning more, visit the starwitness or signalscape websites to learn more. Or if you prefer, PM your contact info to me and I can put you in touch with someone who can answer any questions you may have.
Bill B.