Who hit Franklin in the book Trouble?

In the novel Trouble, Franklin Smith is hit by a pickup truck while out jogging. From a newspaper that his brother, Henry, reads, the reader finds out that the driver is a young Cambodian immigrant called Chay Chaloun.
Later at his pre-trial, a witness (a policeman) states that he saw Chay running down the road, waving his arms in a state of agitation. Chay told him that he had fallen asleep at the wheel of his car and had hit a pedestrian. After it is clarified that Chay was not running away from the scene and has no previous record, he pleads guilty to reckless injury. Much to Henry's disgust, he is given community service and the opportunity to apply for another driving license at the age of 21.