Bought second hand ipad 2 and can't connect to face time it says device is another Apple ID

i bought a second hand iPad 2 and every time I try to connect to Face Time it wants to verify email address. I put all details in and don't recieve the email. When I went in to my apple account it wants me to register the ipad but says it is under another Apple ID. I assume this is the previous owner but don't know who it is.