Jeremy lost his parents when he was nineteen. Just before he graduated from the police academy, they died from a car accident.
That's when John Smith entered the fray. He adopted Jeremy, but was never close to him. He also hid the fact that Jeremy was his son, making him stay at a different house and have his own identity.
The only time that the two would have any sort of interaction was when John would come to the weekly assessment of Jeremy. He trained the boy non-stop so that Jeremy could become his successor in the future.
As years passed, Jeremy became more and more distant to his adopted father. He became a man with different values and different principles, even denying that John was his father.