It appears that The Duchess of Cornwall is a fan of cult Danish TV show The Killing. According to Stuart Heritage in the Guardian, as well as visiting the set on her visit to Scandinavia, she also got presented with a Sarah Lund-style cardigan. Rather worryingly, she was also photographed waving a prop gun around.
Can't see any other puns around for this, so here's my best shot:
Please suggest your own in the comments!