This happens all the times these days.

Go to a police station and file a complaint. Take a picture and send it to that fake account and ask them to deactivate the account. Tell them that their ip is going to be track by police if they dnt deactivate...blab blab. They might be scared and close because its probably someone from your friends school or work trying to bother(stalk) your friend and wants their attention.

If you dnt want to go to the police, just tell them that you will go to the police.

You cant really get help by reporting to facebook.