Runner, by Carl Deuker

Chance Taylor should be on the track team, should be enjoying school.  But living with his alcoholic father who can't keep a job, Chance is living just one step from homelessness and is scrambling to make some money to buy groceries and pay the rent.  When he is offered money for an easy job, he knows it is somehow illegal, but he's desperate for the money, and it's easy to not think about the illegal stuff.  At first.

Carl Deuker has written some great sports books that always involve ethical problems.  In this one, the ethical issues take front stage while the athletics play a smaller role.  A good book from a consistently good author.