It is not your property just because it was found on your lawn. If my neighbor walks his dog through my yard, I can't just say "Hey man, that's my dog now. He was in my yard. In fact, you were on my property too, so give me your watch, your rings and your wallet. They were on my property, so theyre mine." That isn't how things like this work. If a little kids ball rolls in your yard, it is not yours anymore than $600 you find in your yard is yours.
And to Dart, if somebody lost that amount of money, odds are they would go to the police station and report that they lost it. And, if someone turned in said amount of money, the cops would probably call them if a similar amount of money was turned in. It isn't like you can just go in and ask the cops if anyone turned any money in lately and claim its yours.
"Hello officer. I was wondering if anybody turned in any money lately."
"Why, did you lose some?"
"No, just wondering."
"Oh, well, somebody turned in $200 yesterday."
"Really? Well, I just lost $200 yesterday, fork it over bud."
"Okay."
The point is, Manson, you are 15. You are old enough to know the difference between right and wrong. Ask yourself these questions
1. What would be the right thing to do here?
2. Is what I am doing right, or wrong?
3. Why did I choose to do what I did?
The answers are, by the way,
1. Turn the money in to the police.
2. Wrong.
3. Greed.
Anyways, I guess I shouldn't have expected so much out of my generation. I hope you make the right decision.