Columbo, Season Three

Dr. Bart Kepple:
In that case I'm deeply grateful for one thing.

Lt. Columbo:
What's that, Doctor?

Dr. Bart Kepple:
That you've established that White was killed between 7:30 and 8 because you and I have been together constantly since 7:30, starting in the cutting room and ending, I hope, now. Otherwise I'm positive you'd still be accusing me.

Lt. Columbo:
Well, Doctor, I've never accused you of anything.

Dr. Bart Kepple:
I'll ignore that because I'm convinced that my only real protection in this matter is the fact that you personally are my alibi.

Lt. Columbo:
And that's a tough nut to crack.

Dr. Bart Kepple:
That's not tough. That's impossible.