Stolen ipad

If the iPad is signed-in against your AppleID account, you should be able to obtain the serial number from your list of signed-in devices:

Settings > [Your Name / AppleID] - scroll to the bottom of the page to see your devices (tap to reveal details)

Here is Apple’s advice for lost or stolen devices:

If your iPhone, iPad or iPod touch is lost or stolen – Apple Support

Use the Find My app to locate a lost or stolen device – Apple Support

See: Find the serial number of your Apple product - Apple Support

If the iPad has been fully signed-out of iCloud - and the Activation Lock deactivated - you will have no technical means by which to locate or manage the lost/stolen device.

As for the Police, they don’t “track” anything. The theft is recorded - and if your property is subsequently recovered, may help to reunite you with the item.

I guess you have tried all the things my worthless post suggested?