Identity Theft

So I’m not sure where to post this but I need some help and advice please! So my husband got his identity stolen and we are pretty sure it’s his dad that stole his identity. We reported it to the police a year and a half ago (haven’t really heard from the detective since then because they said they prioritize other cases first. We live in Atlanta if that helps). We had multiple collections come after my husband and we were able to dispute it and take it off his report. Now this car loan company won’t accept my husbands dispute and are trying to hold him financially responsible. It’s about $38,000! And when this car was bought, we weren’t even living in the state of Georgia and my husband was only 19-20 when this car was bought. We talked to his dads mom and she said that his dad had the same car that the collections team is after. The company keeps denying his fraud packet even with the police case number. So at this point what should we do? Any help is appreciated! Thanks!