Someone Stole 4k From Me

So basically my husband and I went to buy a car 3 hrs away. Everything looked fine (he’s a mechanic) and then driving it to the notary the check engine light was blaring so he crawled under the car after the lady was counting the money in the notary and then she must have saw us out there and she ran off with our money. We discovered the massive oil leak from the main rear seal, so I messaged the guy and asked for our money back, he tried arguing with us. We did not transfer the title. So I called The police who are now involved and all he officer told us was if he didn’t give us our money back they’d both be charged with grand theft. (They were on the way to a different state apparently and couldn’t come back to return the money) They both own 2 businesses, not that that matters but they obviously don’t need the money. so he agreed to send a certified check on Monday but I asked him if I could come pick the cash/check up instead after he told me I could come back Monday. Then he said he’d rather mail it. If I just drive out there to his business with the officer would he be required to give me my money back or be charged. Is there a limit on how much time he has to return it?