"It remembered being turned off. And then turned on. At exactly 9:14 PM. Right when you were supposedly stuck in traffic. But here’s the kicker... the bulb remembers the voltage variance . That old house of yours, the wiring is a bit shoddy in that panic room. The voltage dipped. A dip like that happens when the heavy-duty safe motor is engaged. The one you used to lock the room from the outside."
(Sneering) "Lieutenant, this is absurd. A broken lightbulb?" columbo
"It’s not broken, sir. It’s just... lonely. You see, this is a specialized Aether-Smart Bulb. It records usage data. Even when it's unplugged, it holds a charge for 24 hours to keep its memory. We plugged it in at the station. You know what it remembered?" "It remembered being turned off
The show’s rogues’ gallery is unusually sophisticated. Almost all are: Right when you were supposedly stuck in traffic
Thorne freezes. The realization hits him that his obsession with control created the evidence.
Columbo discovers that the victim was an audiophile who listened to vinyl records. The record player was in the panic room.