Can a roommates past keep you from getting a security clearance?

Yes, a roommate's past can potentially impact your ability to obtain a security clearance. Security clearance investigations often consider the character and behavior of individuals close to the applicant, including roommates, as part of assessing the applicant's reliability and trustworthiness. If your roommate has a history of criminal activity or other concerning behaviors, it may raise red flags during the clearance process. However, the ultimate decision will depend on the specific circumstances and the nature of your relationship with the roommate.