I love Columbo and I'm sure I have seen every episode more than twice, BUT...
These modern CSI procedurals have changed the way I watch our favorite Lieutenant.
When Columbo stumbles around a murder scene smoking his cigar and dropping ashes, or brings a hard-boiled egg to the scene for his breakfast, then cracks and drops egg shell bits all over the scene, and rummages in the victim's fridge for orange juice...I just yell "CONTAMINATION" at my tv, but Columbo keeps on mucking around touching stuff, moving stuff.
When he does find forensic evidence that might be useful, he carries it all over town in a paper bag or in the pocket of his raincoat, so that he can pull it out in the final big "GOTCHA" scene. But as the cops who carried O.J. evidence around town without logging it into the system found out...Defense attorneys can destroy your case when you get careless with the evidence.
I think I figured out why he was still a Lieutenant 20 years after we first met him--it was because he always "caught" the right guy, but NO evidence ever got admitted in the court case and all these rich guys (villains) got off just like O.J.
The 70s and 80s were the era of "new" technology. It was always fun to watch as the villain of the week tried to use the newest gadgets (mobile phones, call forwarding, VCRs, etc to pull off the perfect crime, but Columbo always figured it out.
Here's a little bit of trivia: In "Etude in Black", actress Blythe Danner played the wife of murderer John Casavetes and in one scene was very visibly pregnant. That little "baby bump" later became Gwyneth Paltrow.