If you handed it in then you would have to be asking the cops (or whoever you handed it into) if they would keep it or do the 'right thing'. Odds are they would do the same thing any other random person on this forum and keep the money.
Unless i personally knew the one who lost it, and i knew they worked hard to earn it, then i would have a sympathy for them. Other than that im keeping the dough.

Mississippi Steve - dont talk shit about peoples parents and how good a job they did or didnt do. My parents did a great job raising me. They taught me a great number of things, and one of which is how to make decissions for myself. So please dont go around playing the roll of the good sumaritian acting like you know whats best for everybody, because quite frankly you dont.