Who is the children's attacker and how did he die in to kill a mockingbird?

In the near; or last chapter, Bob Ewell attacks Scout and Jem while they're walking on the sidewalk. He planned to do this to "get back at Atticus" because he humiliated him, etc.

And Ewell ended up breaking Jem's arm, but Arthur "Boo" Radley save's him. Scout got away before this, running.

In the end, Ewell was killed by Boo Radley; but in the claims it says he "fell on his kitchen knife."

This is because Boo Radley saved them from him, so the cover up was necessary.