Question about child services and covenant house?

Please if anybody can help I will appreciate it.. My 16yr old nephew ran away from home he was reported missing 3 weeks ago. He recently contacted me to let me know he is okay. I dont know where he is staying but he told me he wanted to come live with me. He contacted child services himself prior to calling me and now has an open case. So basically my question is what are the procedures I can take. I dont want to trick him into going to the police because they will just send him back home and runaway again. So please what can I do? Fight for custody? Please give me an idea im clueless and just want him to be safe. thanks