Tom and Jerry are hanging out in a park one night when they are approached by Fred and Barney. Fred and Barney were in the mood to cause trouble so they challenge Tom and Jerry to a fist fight. Fred and Barney have no weapons but continue to threaten Tom and Jerry telling challenging them to a fight. As Tom and Jerry start walking away, Fred punches Tom and Barney punches Jerry. As Fred and Barney start walking away laughing, Tom pulls out a gun and shoots Fred, killing him. Tom points the gun and Barney and tells Barney to give him his wallet and phone or he will shoot him, so Barney hands over his wallet and phone to Tom and runs away. Jerry witnessed the entire exchange between Tom and Barney. Tom gives Jerry Barney's phone but keeps Barney's wallet for himself.

Assuming the perpetrators had the requisite mens rea for their crime, who committed a crime in this fact pattern?

What crimes did each individual commit?

Do the individuals that have committed a crime have a good defense?