In The Fast And The Furious why did Johnny Tran kill Jessie?

Johnny Tran wanted to kill Dominic "Dom" Toretto and take some members of his family too for assaulting him and one of his buddies on the race track earlier. Jesse was the one who ran out during a drag race in which he race against Tran and he lost so he was suppose to give Tran the keys to his modified 1995 Volkswagen Jetta but didn't which provoked a fight between Tran and Dom.