Just saw this one again. I have to say it is one of the poorest episodes (but not as bad as all-time worst "Mind over Mayhem").
Vera Miles is not bad as the murderess, but they make her character very uninteresting. Martin Sheen, who is a very good actor (he was super as Robert E Lee in "Gettysburg") was absolutely terrible in this one, but fortunately, he was bumped off early so we didn't have to suffer too much with him. There is very little evidence against Viveca other than the scratchy hand. What I find odd is that Columbo didn't make much of the death of Shirley Blaine whose accident must have occurred near Viveca's "Fat Farm" and the fact that an autopsy would turn up drugs.
A general lapse in quality for the series.