You shouldn't jump people.
"Frank lives in the city and finds out that a ""friend"" of his just stole a lot of his money."
Frank wants to get justice on this friend.
Frank reports the friend to the police and describes the theft in detail.
Frank gets some friends, finds the thief when he's alone, and attacks him.
The police arrest the friend and recover the stolen goods.
The thief fights back, escalates the conflict, and turns it into an all-out war.