He might have noticed that he lost his driver's license. Some people are notoriously bad at hanging onto their things, including ID. Did he go to DMV after police searched his car and place? He's been in so much trouble for not having driver documentation that he might finally have gotten through his head that he had better have all his paper work and ID and that he could have charges filed for driving around without a license if he can't locate his. Too bad for him, he didn't think about not driving recklessly from the PD.