Legal Alien: A Scotsman in Montreal

 
Friday Fun pt II - y'know I could make these impossible to solve, but then where'd the FUN be?

Nasty Norris was responsible for Simple Stevie's death. He did not kill him in person. He hadn't even seen him since 10 years before. He sent the weapon through the post with a birthday card.

Stevie died exactly as Norris had planned.

The card touched the weapon, but the card never reached its destination.

How did Norris do it?