Issues with startup configuration

So my question might be a bit unorthodox. A year ago I found an iPhone 4 and had turned it in to the police. They have contacted me last week telling me that as they couldn't find to whom the mobile belonged to, I am entitled to claim it, and I have done so. The trouble is that when I tried to configure it with iTunes, it was still registered to its previous owner and naturally I do not know who that is so I can't do anything through iCloud. Is there any way around this? When I turn it on it shows up as startup configuration and there's no skipping it.