As has already been mentioned, "Death Lends a Hand" really benefits from strong performances from the leads: Culp is an incisively self-assured murderer; Milland oozes sympathy and compassion as the widowed man etc. etc.;

The plot twists the woman-cheats-on-husband theme very effectively, but the best aspect of this episode is how Columbo subtlety questions and contradicts Culp's characters's theories and suspicions.

The way Columbo "gets his man" is terrific; the hitherto confident yet volatile murderer is slowly undermined by Columbo's well-aimed, provocative assessments of the clues. The irony is that Columbo lies about the missing contact lense to unmask the killer; it is vintage stuff.

The ending reflects the quality of the overall episode; unlike two other otherwise excellent offerings from Season 1, namely "Murder by the Book" & "Lady in Waiting" which effectively cheat the viewer with unconvincing endings.