He was turning into the police thus he did not keep it. So the police would have it and I believe depending on the state the # of days can vary before he could go back to get it if it remains unclaimed. But I assume he isn't required to go back to claim it and then I assume the state just gets to keep it as unclaimed property.Hate to be the bearer of bad news, but...
From IRS Pub. 525:
If you find and keep property that doesn't belong to you that has been lost or abandoned (treasure trove), it's taxable to you at its FMV in the first year it's your undisputed possession.