MLB stadiums: If you enter the field of play after a HR ball, can you keep it?

I’d guess this may depend on the city or state where the stadium is located, but the Bonds HR chase made me wonder about this question. If a home run ball bounces back onto the field, or goes into the bullpen or something, would a fan be allowed to keep it if they went after it? I know there are penalties for entering the field of play (trespassing, disorderly conduct, ect.), and proabably significant fines to pay. But, considering that Bonds’ record breaking HR ball could fetch 7 figures or more, any fines would be a small price to pay for getting the ball. If somone went onto the field, or into a similarly resricted are of a stadium, would they be allowed to keep the ball? Or, are there rules or laws in place which would give the ball to someone else like the team or MLB?

No. Fans who enter the field of play, or interfere with balls that are in play, are invariably relieved of the ball by security. You are entitled (by legal precedent, incidentally) to keep the ball only if it goes out of play.

If Bonds’s 756th does not end up in the stands, nobody will get the money.

I would not be so sure of that. I bet a player on the field could keep the ball, just like Doug Mientkiewicz did with the winning ball from the 2004 World Series (well, for a time anyway before it went to the HoF). FWIW, this Wikipedia article cites the MLB saying that he did in fact own the ball (and not the Boston Red Sox, who claimed it was theirs since they were the winning team… or something)

If you entered the field of play to go get a baseball, you would likely be found guilty of criminal trespassing. Presumably, you can’t commit a crime, even a minor one, to take possession of something that isn’t yours to begin with and assert possession of it.

Teams will announce that fans are free to keep to any balls hit or thrown into the stands, so they are only allowing you to keep it because they are being nice. It was common practice until the 1920s to have ushers get the balls back and in Japan that was the custom until the early 1990s.

The Japanese fans gave up the balls without any argument most of the time. Today, fans believe that they have an inalienable right to a baseball.

They don’t. My feelings for these people are Pit material.