I've found an icloud locked iPhone, how can I return it to the owner? A friend of mine found an iPhone 6 in a festival but she didn't have a way to charge the phone for a couple weeks. She is a maid here in Brazil and didn't have the proper charger neither knew how to use the phone. When she finally gave the phone to me to charge and try to find the owner, I've found out that the phone had an iCloud activation lock. 

We took the phone to the carrier but they said that the sim card was deactivated already and belongs to a corporate account with more than 100 numbers associated. 

Is there a way for me to contact the owner via Find My iPhone or iCloud? If I wipe the phone, start over and try to activate will that notify the owner via Find My iPhone? If that happens maybe I could just put another valid sim card and wait for the person to text me via iCloud and I can text him back to see how I can return.

I don't want to take it to the police because I'm pretty sure they will just sell the parts (the Brazilian police are super corrupt) and I really want to return this phone because I lost mine already in the past and I was very glad that the person who found returned it to me.
If the SIM card is deactivated, replace the SIM card with one that is functional and will provide the device with a data connection. This will allow the phone to communicate its location to Find My iPhone which the original owner can use to locate the device.

You can't restore a device with an active Activation Lock (except DFU and that just puts it back in Activation Lock), so “wiping the phone” isn't a possible avenue.