I was on the bus in downtown LA?

I was on the bus and this skid had left his backpack, I noticed him walk off without it, so i went to grab it and jumped off on the next stop, i couldnt find him anywhere so i took the bag home, when i opened it to find ID all there was, was $750, and a huge bag of week, My parents were gone that weekend, so i had a party, and needless to say the bag is now empty, should i keep the money, cuz if i track the guy down, he will be pissed i smoked all his gr???