Thread:Avatar Raava/@comment-26844696-20160103154037/@comment-26402117-20160103204723

What you can do is check "Automatically block the last IP address used by this user, and any subsequent IP addresses they try to edit from" for the alleged impersonator or sock. If that's done and the original user is still around, then you can safely eliminate the users being the same.

Not that this is an absolute check - it very rarely may throw up a false positive.