What evidence does atticus discover that suggests that bob ewell was killed by boo radley?

He was killed by like butter knife or a type of knife because Boo was trying to save Jem and Scout. Hope it's right. 

Well based on the summary,   the setting plays a big role in char. development since the cat has been spoiled and babied her whole life she has to figure out how to survive on there own for the first time. and since winter is coming the cat is faced with lots of dangers and troubles. but, like you said with the storm that brought an invasion of rats, since she is   a cat shell figure out how to kill and get food and the storm is the best way to learn right. can you mark me brainliest pls! read more on -