Confused about film plot and timeline
Okay, can any of you guys help me here? I'm someone who wants to be a filmmaker, and because of that I sometimes look at random movies both new and old to admire their cinematography, production design, directors, and actors -- and the other day I decided to watch 1997 film "I know what you did last summer", and was confused about it's plot and storyline.
So for those who've seen the film know it's about a group of teenagers who one night run over a man on a dark road one evening when driving home -- and they believe they've killed him. As a result of believing they've killed him, they then try to dispose of his body to try and hide it and their incidental murder of the man.
They find out the man is still alive when trying to do so, and then they end up trying to consciously kill him and dispose of his body to prevent themselves from getting in trouble for what they've done. Eventually the man who got hit ends up killing many people and a few of the teens who tried to kill him, and it's all because of them trying to do so instead of not and saving him. He never tried even after the consciously tried to kill him, and incidentally almost did by hitting him with their car.
Before the car wreck happens, the storyline proposed that a year prior to it the man who got hit experienced his daughter getting killed in a car crash -- and he and her boyfriend survived her.
The night the man was hit my a vehicle, his daughters fiancé allegedly killed himself according to the local news in the storyline, or the man who got hit that evening killed him for some odd reason according to one of the teens I'm about to mention.
The girl who ended up figuring out the man they tried to kill, who was one of the teens mentioned, was still alive and trying to kill them -- thought he killed his daughters fiancé and that they had mistaken the fiancé for trying to kill them before they knew it was the man they hit.
It's all a little confusing, and it all doesn't make sense to me -- and I don't even know if my question makes sense, but I want to know if that man who was hit killed his daughters fiancé. Did he kill him? Or did the fiancé kill himself? If the man who was hit killed him, why did he? If the fiancé killed himself, why did he?