A lot of the murderers would not be found guilty - SPOILERS
I've been watching the show over the past few weeks. I'm up to season 3.
While Columbo does find out who the murderers are, IMOH, some of them would be acquitted in court.
In the episode in London, he had to plant evidence (when he threw the pearl into the umbrella)
Another episode, his proof was that he had a recording of the murderer's phone call, the murderer claimed was from his office. We saw it was from a pay phone. But Columbo's "proof" was because he didn't hear the clock in the office chime on the hour.
Other episodes, it's mostly a theory and he's completely dependent on a confession.
You thoughts?