Why Boo?

In Last nights reading there was a man whose shadow Jem, Scout and,Dill saw. He was very close to them and it looked like he was going to grab them. He eventually walks away and the children freak out and wake up mr radley. Jem leaves his pants and when he sneaks in to find them again he sees that they were sown up by what looks like a child's hand. Jem is stunned by this and this adds to the mystery. Next in the knothole by the radley place they find some yarn which they make theirs. I believe that this person is Boo Radley. With every chapter there is more and more mystery. The knothole and gifts, the mysterious figure, and the sewed up pants. Lets try to inspect the evidence. The shadow was a tall man with a hat. This gets rid of any women in the town as our suspect. This also gets rid of the idea that a child has been filling the knothole. This is assuming that all the evidence is connected. The pants are the next clue. Someone stitched them up and got them ready for jem as if he knew that jem would need them. Then there's the knothole this is completely odd. Both the pants and the knothole are acts of kindness, but why would someone start putting random stuff in the knothole. So far we have some gum, pennies in a ring box, and some twine. The only reason that I can figure out without further evidence is that these things represent something, and i'm terrible with secret messages. These acts of kindness just add to the mystery because they are so unpredictable. The only solution that I can come up with is that these objects will help us learn about Boo. The only answer is Boo because he has the opportunity he lives by the knothole, he is a man and could have easily seen the kids, and he could have fixed jem's pants. However, why did Boo do these things?