Lt. Columbo deliberately obscures his first name as protection from Death NotesThis ties in with the Death Note theory that Columbo is L's grandfather. The family has known about the Notes for some time, and Columbo hides his first name from everyone in case one comes up.
Lt. Columbo is the mentor to Robert GorenAt some point, Goren studied Columbo's full case history and his methodology, learning as much as he could from them and then adapting them to his own use.
Lt. Columbo isn't human.He's one of the Erinyes, also known as Furies, ancient Greek female demigods of vengeance that, as often as not, punished those who showed hubris against the gods (which is about all they cared about) in their otherwise non-Fury notable crimes. Most of Columbo's perps are generally smug and arrogant, and go to great lengths to hide their crimes. No one believes in furies anymore, and just to have something to do in retirement, Columbo pretends to be a shabby homicide lieutenant in a otherwise random city full of murders by people who have to time to plan these things. He might even be Nemesis herself, and her gender flip is just a nod to the times. The wife, the brothers-in-law, the nieces and nephews, none of them exist. A little divine magic keeps the cops confused but generally accepting of the Lt. coming in on another case. The dog is a retired hound of Artemis, because all dogs dream of being as lazy as the average Bassett hound. Notice, Columbo rarely chases dead ends or red herrings, and more often than not, the killers are rich and powerful people who see themselves above the law. Usually, the person he spends the entire episode irritating is the person that committed the murder, no matter how well they hid the evidence and covered their tracks. Even if everything points to another person, Columbo is still off getting up the nose of the person the audience knows from the beginning did the deed, even if he has no proof. Columbo just knows. He doesn't arrest them, of course, because part of their punishment for the arrogance of both hiding their murder and committing it in the first place is to be utterly humiliated by this little shabby, squinting cop with with broke-down car and cheap cigars.
Lt. Columbo is a sociopath.He lies without hesitation in order to catch the culprit. He even fakes feelings. He once faked being in love. His greatest thrill is using the legal system to kill his victims. Yes, some of his victims do get killed — the death penalty was legal in California during most of the original run.
He does not carry the real evidence around with himCome on, this is not a stupid man. It's rather likely that Columbo obtains copies of the evidence to haul around with him. While he has displayed the actual evidence on occasion he's probably not going to put murder bullets in his pocket or into paper bags where they could be lost or tainted. If he really was doing this, almost all of his cases would be thrown out.
Columbo and Quincy are set in the same universeGary Walberg, the actor who played Lt. Monahan in Quincy showed up as an unnamed police sergeant in an early Columbo film Lady In Waiting. Maybe he later got promoted and moved to another precinct?
Coloumbo's wife is smoking hotShe's enough of a looker for Columbo not to chase women who look like Faye Dunnaway.
Columbo's "wife" is actually his husband.You never see his "wife" because he doesn't have one. He doesn't chase hot women because he's not into women. He's gay, and lives with a male partner. His fellow cops might know the truth, and just turn a blind eye. Being gay in the '70s may not have been as bad as it was in other decades, but the stigma was bad enough to warrant secrecy on the part of Columbo and his partner.
Grace Wheeler was suffering from ill-effects of her condition when she shot her husbandIt seems her plan to kill him was cooked up on the spot, not premeditated, after he refused to fund her return to the stage. Then not a few minutes after the killing, she promptly forgot about it. Upon discovering the body and through the rest of the episode, she genuinely did not know she had killed the man. Besides memory loss, her condition caused brief psychosis- enough to kill a man out of greed. She certainly didn't seem to be the homicidal type otherwise...
Lt. Columbo is suffering from nightmaresThat's the reason he always appears tired and distracted, especially in later seasons. All the deaths and sometimes grizzly murder scenes he sees keep him restless at night. Also the reason why he keeps himself distracted with trivial things around him, it suppresses the memories.
"Columbo" takes place in the same universe as Star Trek.Assuming the spin-off series Mrs. Columbo is canon, the lieutenant's wife bears a remarkable resemblance to Captain Janeway. Columbo also once dealt with a murderous surgeon who looked and sounded remarkably like Spock (who we know is half human). Columbo also dealt with a family named Paris. In the Star Trek universe, it's commonplace for Starfleet officer's ancestors to look and sound astoundingly like them. Conclusion: a lot of Starfleet officers had ancestors who lived in L.A. in the 20th century, and crossed paths with Lt. Columbo.