I do a lot of knitting while watching episodic crime series. A number of these are American but regardless of who made them I am always on the lookout for new ones so leave a comment if I've missed a good one. I acquire these episodes in a way that pater, as a solicitor, would not approve of but they are generally available on services like netflix or sky+ and so on. I'll go for alphabetical order.
Lie to Me
Miss Fisher Mysteries
Murder She Wrote
NCIS: Los Angeles
I'm sure I have forgotten a few (some, like Columbo, are deliberate) but leave a comment to let me know if I'm missing anything good.