Well, I have my doubts if this is a legitimate posting but for the sake of playing I will put forth my 11 and a half cents:
If you do take it to the cops you will likely never see it again. As another poster already indicated, they will find some way to keep it for themselves. Or even worse could occur. A fellow in our town found a phone, turned it in to the cops, and a week later was arrested for "possession of stolen property." His PD told him to plead guilty because his prints were on the phone and that is all that was needed to get a conviction. Due to recent changes in the law, prosecutors no longer have to establish guilt, Mens Rea is almost dead in the water.
Anyway the poor guy now has a felony conviction and can't get a job, all because he "found" a phone. I'm not saying that you didn't find this phone by your pool but let me say that the circumstances that you describe along with your "english" (you say you feel a little "weirded") sound a little strange to me. If you are that paranoid about your neighborhood, buy a gun or get some high resolution cameras put around the perimeter of your house.
As far as getting past the security code on the phone screen, well that's a piece of cake. But please don't ask me privately how to do it. If I were you I would just dig a hole and bury it.