If you have a security clearance for your occupation and end up getting charged for a criminal or drunk driving offense, you may be worried about losing your clearance. And with good reason. You will have to fill out a form when you renew your clearance, and there is a question on the form asking if you have been charged or issued a ticket for any criminal or drunk driving offense.
Notice that the question is not whether you have been convicted, but rather if you have been charged. These are two very different things. Anyone can be charged with anything at any time in the US, but it takes the government proving your guilt beyond a reasonable doubt for a jury to convict you.
The agency reviewing your clearance form does a "whole person" analysis, which means the agency considers whether the entirety of your profile would qualify you for a clearance. There is no bright-line rule as to whether your charges or convictions will disqualify you.
This is important for two reasons. First, you should not assume that any one charge or conviction will automatically cause you to lose your clearance. And second, even if you beat your case in court, you still must explain and mitigate your charges. For example, if you get drunk driving charges dismissed, it is still a good idea to enroll in some sort of alcohol counseling anyway to smooth over the fact that you got the charge.
Still, there are some general rules to consider. One is that if the court is lenient with you, the panel reviewing your form will look favorably on that fact. Another is that domestic violence convictions are usually an automatic disqualifier.
The best rule of thumb is that you should work with an experienced criminal law attorney to ensure the best possible outcome with the least amount of risk. Even if you lose your security clearance, you still need to position yourself for obtaining other employment by minimizing the hit to your criminal record.