Oh heck.......don't struggle anymore.....you got it.
All those I listed did not have a murderer killing their spouse.
In Requiem and How To Dial A Murder, they probably both killed off their spouses...but that is not the case that Columbo is working on.
And in A Deadly State Of Mind a spouse is killed while the wife is there, but it is Collier who strikes the fatal blow.
As I said, I should have listed the episodes where the spouse is killed instead of the other way around!! The list would have been a heck of a lot easier to type!!
Great Job E!!!