[mothered]

I assume that the package had the same weight as the laptop.

Yes I know, the OP stated that In his/her Initial post.

By mentioning "evidence", I was referring to what Indication will the OP provide that's consistent with a missing Item. There's no point If the package Is In a perfect (sealed) condition without any assertion of tampering.

What if he showed a receipt from the post office that had the correct weight on it?

Weight verification will certainly help to confirm that the Item was shipped In the packaging/box.

However In terms of the Item (laptop In this case) gone missing, proof must be provided that the box was tampered with. In short, the Item was In fact shipped (confirmed with the matching weight), but where's the evidence that suggests the laptop went missing during transit? You cannot send a perfectly sealed box with no evidence of tampering, and then claim the Item Is missing.