Sebastian is the second person I have come across with Bipolar Disorder, the other is a close friend of the family. The old name for this condition is Manic Depression and people who have it switch (almost at random) between a low state where they are the most depressed person you have ever seen and a high state where they want to put all the world's troubles to rest. In a high state someone with Bipolar Disorder can have some pretty crazy ideas, ideas such as launching a pro se case against the local Police Department, so maybe this could explain some of his actions.
False IDs? Forgery? Alcohol to minors? Impersonating a police officer? No idea about those but diagnosed Bipolar Disorder would be a pretty good defense. One thing is sure, Sebastian needs help and he needs to be taking his medication on a regular basis, the staff at the jail will hopefully make sure that this happens.