1. If the case is closed, does it just go away or are cases like this periodically reviewed? I’m curious to know if any of this will come up in the future again.
If ti is closed, it is unlikely to be re-opened absent some new evidence that might compel someone to re-open it. If you are asking if the case is over, done, and tossed into a scrap heap never to be seen again, the answer is, "Not necessarily."
2. Does being a suspect in a criminal investigation affect any government clearance(current status or during clearance renewal)? I have one for my job currently but it will need to be renewed in a few years. I just want to make sure I don’t have to deal with this issue at that time either.
Maybe.
There are no cookie-cutter background investigations so there is no way to tell if your being a suspect in this matter will effect you or not. If your position requires certain CONVICTIONS in order to be disqualified, then it likely will have zero impact. However, if for a government security clearance, your involvement may very well have an effect ... but that depends on the position, the clearance, etc. There are a couple of posters here that can provide greater detail on this particular aspect.
3. Does something like this have a statute of limitations?
Most crimes have statutes of limitations. So, yeah, it probably does.
4. Can a detective use discretion during a criminal investigation (ie - choose not to investigate further) or is that decision up to another party (prosecutor, captain, etc)?
That is a matter of internal policy. Sometimes, yes ... sometimes, no. It might be that the detective will need a supervisor to sign off on closing it out ... or, it might not.
Lastly, where would be the best place to find a cheap (but good) criminal defense lawyer for the state of Maryland who specializes in this type of case if I would need one? Pro bono preferably.
Check with a local law school or bar association for information and referrals. Don't count on
pro bono aid.