i'm sorry you keep having reminders of the very thing you're trying to get past. i agree with sofa. his parents are HIS parents. in time, hopefully they will understand how you've felt all this time. try not to take what they are saying too personal either, after all, you already know they are in denial so everything right now, has to be someone elses fault.
even though the cops came to your door, you are not involved just reminded of a probable reason why he's not there in the first place. still praying for you both.