You don't need to be. I didn't know the murdered spouse. It happened long, long ago. It was just a curious fact to be not so far removed from a famous murderer, to the extent that I heard some of the backstory several years ago. I thought it sounded a bit familiar.
I have a similar relationship at one remove with another person who was randomly murdered with his wife. I feel a bit like Miss Marple. She is so frequently present, you begin to suspect she was involved!
Fortunately for me and your suspicions, in both cases, it appears the murderer has now been caught!!!