I'm really confused about this story. It says they used compared the DNA of the fur on the jacket and it matched the cat the two had. How does that prove that Beamish killed her? I'd always have 1 or 2 cat hairs on my clothes when I had them.

edit: NVM, saw they were estranged, so presumably not living together, which would mean he transfered the cat fur to her clothes when he murdered her.