His mother had reported him missing with the police on Oklahoma and she comes to LA where the character admits the abuse. The question is what procedure would agencies such as the police and social services use concerning the abuse? Particularly when they return to Oklahoma
I have researched that the statue of limitations on the abuse will not run out until two years after the character turns eighteen. Will the police or social services in LA contact the agencies in Oklahoma? How quickly would an agency visit the character and his single mother? Which agency would take the lead? How likely is it that any arrest or trial would take place considering that it's been two years since the abuse and there is really no evidence? How would they treat him as he's now a teenager (all of what I've found on google has focused on interviewing children)? Would the police want to talk to him before he saw a therapist? Would the police take his statement outside his home?
Also the abuser has been abusing another child in the two years since the character ran away. I'm assuming that the police investigation would turn that up and would focus there instead of on the character who ran away.
I googled "police procedure for child sexual abuse", "Oklahoma procedure for child sexual abuse", "procedure for teenager who has been sexually abused as a child". These pages have been useful so far http://www.childwelfare.gov/systemwide/laws_policies/state/index.cfm?event=stateStatutes.processSearch and