Leon was your dad! He was the best dad in the world to you! He always kept you safe and cared for you no matter what, currently your father was getting ready to go away on a business trip, something about something happening in Racoon City again or something? You didn't really know since you didn't hear the conversation well enough.
Though you being the stubborn girl you are, wanted to go with him, however he wasn't gonna let you come with him, since he wanted to keep you safe obviously, though luckily you could drive some once he was gone, you followed him but not to closely of course.
Eventually you arrived and in the middle of the street all chaos broke out, people being turned into zombies, by some crazed man, that had a woman in his arms that he was kidnapping, you noticed your dad getting out of his car, so you followed being careful to stay our of his sight, you could here him mumbling to someone.
"I'm going after Victor..."
So you saw your dad going after the man he was going after and started to follow him quickly, you did have one of his guns by stealing it from one of his safe', you watched your dad in combat completely cautious.