The answer is: Bob Ewell
In Harper lee's "To Kill a Mockingbird," after Scout and Jem are attacked by Bob Ewell, the sheriff Mr. Tate decides to protect Boo's seclusion and claims Ewell fell on his own knife and died. In that matter, the switchblade is the same that Ewell used to physically assault Scout and Jem, suceeding his destroyed credibility at the trail and constant threats to Atticus' family.
