How can I unlock a iPad if the previous owner had died and I do not have the previous owner password

Apple can completely erase a device if a person can provide sufficient evidence of valid ownership. Do this online here -->Activation Lock support request - https://al-support.apple.com/#/additional-support Apple says, "Proof of ownership documentation is required," but does not state what constitutes proof. Prior to this new online service Apple typically required the original receipt issued by an Apple Authorized dealer and documented provenance (so typically it would be the original owner who does this, or a descendant with legal proof of ownership).