In the movie In Time, when Timekeeper Raymond Leon meets main character Will Salas for the first time, he teases him by talking about Will's father who was too young to know him when he died. He also implies he knows what really happened to him, but we never learn what. What happened to Will's father?
Both point indicated that Salas father's death is a mystery and only his wife and Leon know about it. It kept mystery in the film till end.
As per intime.wikia.com