Original owner is deceased

In this situation it is the inheritor of the iPad who needs to get Apple to grant access to features that will let the lock be removed. If Apple itself does not erase the iPad as part of this, the inheritor will then do the things in this article: What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support

An exception might be if you have the original receipt for the iPad's purchase. Apple can completely reset a device if a person can provide sufficient evidence of valid ownership. Do this online at: Activation Lock support request - https://al-support.apple.com/#/additional-support Apple says, "Proof of ownership documentation is required," but does not detail what currently constitutes proof. Prior to this new online service Apple typically required the original receipt issued by Apple or an Apple Authorized Reseller and documented provenance (so typically it would be the original owner who does this, or a descendant with legal proof of ownership). This will give you access to the device but won't restore access to the account used to lock it. There is nothing that can be done to expedite an Activation Lock request.

Apple recommends you "Keep your receipt after you buy an Apple device" --> Keep your receipt after you buy an Apple device - Apple Support

For information about how to request access to a deceased family member's Apple account data, and possibly their equipment, click here --> How to request access to a deceased family member's Apple account - Apple Support

Apple says:

"While we may also be able to help remove Activation Lock from devices that use your loved one’s original Apple ID, their iPhone, iPod, and iPad will need to be restored to factory settings before they can be used with another Apple ID. Please note that devices locked with a passcode are protected by passcode encryption, and Apple can't help remove the passcode lock without erasing the device."