@SW-User
Columbo had evidence that the victim never left the vineyard after seeing his brother. Since he died of suffocation, the only place that could have happened was the wine vault. And it could only have happened if the ventilation was switched off. There was no reason to turn it off except to kill the victim. The wine was spoiled, due to over heating. It established the means. Means, motive, and opportunity was what Columbo needed to convict.