The thing with Columbo vs Kira is that in reality it'd be over in one episode. Kira is Columbo's bread and butter - he deals with self-important shitbags like this literally every day; it probably wouldn't even stick in his memory very much if not for the Death Note.
Would he be able to intuit the actual mechanics of the Death Note before laying hands on it? Probably not. Would he be able to intuit that Kira needs to write down someone's full name before they can die? Abso-fuckin'-lutely.
Kira thrives against someone who is ACTUALLY unsure, eccentric, and trusting of people in their inner circle, which is why L is such a perfect opponent! Unfortunately!! Columbo just plays up his uncertainty to get in close with people who don't see him as a credible threat - and strikes before they can do anything!
But, I hear you asking, how exactly would Columbo defeat Kira?!
Kira started killing people within the same time frame as a Japanese high school student. He then stopped doing this as soon as the police squad figured it out. Kira has to be someone in high school in the police squad's immediate family, or someone who was in the room at the time. Columbo can keep tabs on everyone in the squad - none of them are able to fit the killings into their schedule, and most come back home way after anything begins happening. Oh look, the captain's kid is in high school and might be a good place to look!
Columbo knocks on the door, gets invited in by the Yagami family, and asks some basic questions about their daily schedules - see, he's thinking Kira might be trying to frame people on and around the team trying to find him, because that kind of scandal would get them all shut down pretty quick. He asks Light some questions about school, cracks a joke about "back in my day, exams-" and then asks to use the bathroom.
There's one upstairs - Columbo makes use of it without a hitch. Light, seeing his chance, goes to his room to put the Death Note in a more secure place. He's met by Columbo just outside, who wanted to ask if he could borrow a pen ("sorry Mr Yagami-san, I must'a forgot mine at the station") and Light, not wanting to seem suspicious, lets him into his room.
Columbo writes down some weird-looking notes on a scrap piece of paper from his pocket and tops them off with a little "Innocent" heading, which Light espies despite affecting to be looking away. Columbo mentions how nice the pens they have here are - how his wife back at home wishes she could have a real nice pen like that one over in the States, one that really glides over the paper and lets you write however you wish ("see, my wife, she's a bit of a slanted writer, and y'know she doesn't really like how a lotta pens just sorta give out when you're writing at an angle-"). Light just gives him the pen and says it's fine, just to shut Columbo up.
Afterall, what could be incriminating about a pen?
Columbo says his goodbyes, thanks the Yagami family (Light's dad has just come back) kindly, and leaves in his battered old car. The captain says he's a bit of an idiot, but his heart's in the right place, hopefully he wasn't too much of a bother? Light, once again avoiding suspicion, says Columbo was nice and courteous.
Columbo now knows that Light keeps his door alarmed with pencil lead (saw it while standing just outside his doorway), that Light felt the need to put something away quickly while Columbo couldn't see, knows that Light thinks he's in the clear, and knows that if Kira starts making moves to make it look like he's framing the police squad, then Kira must necessarily be one of the people in the Yagami household. He also has Light's pen.
It takes very slightly longer than usual for the next day's killings to start, and in the meantime Columbo gets the recent sales figures for the local stationery suppliers under the guise of knowing when the station would be best served restocking their pens. He finds the date and time Light's pen was bought.
Now Columbo knows that, since Light is an organised kid, he doesn't take his home pens to school with him and risk having to go out and buy more if anything happens to them at school. He also knows that, based on how little ink has been used (relatively speaking) this can't be the pencil/pen Light uses for homework, because if it were a new (little-used) pen, Light would've probably mentioned, and offered Columbo another, older, pen. Having checked the stats of this type of pen, and experimented with another one bought from new, Columbo can now see it's been used approximately as often as you would need in order to describe every killing Kira has committed to a reasonable level of accuracy. He also knows that Light forgot he'd given his pen away to Columbo, and spent a few minutes getting the ink flowing in his other pen before beginning to write. Incidentally, the first of the Kira killings which Light could get written around his schedule took about half a minute longer than expected.
Columbo now understands that whoever is doing the Kira killings is orchestrating them by way of writing, though it's happening alarmingly fast - too fast to be explained normally, at least thus far. Some of the killings from that day fit Light's schedule a little too well, and the detective checks in with the Yagami family while Light is away at school.
Hearing that the detective was in the house when he's not around, Light acts as cool as he can while internally panicking a little and quickly checking on the Death Note in the fake bottom of his desk drawer.
Columbo, watching from the street, walks over now to the front door and apologises, saying he wanted to return the pen he borrowed from Light. Light's mother sends him up to Light's room upstairs, since she's got her hands wet at the moment and doesn't want to ruin the pen.
Columbo knocks on Light's door, startling him and making one name on his list of killings (a death row inmate from Canada) illegible, and thus unable to die from the instructions in the Death Note. Light shoves the Death Note out of the way and greets Columbo as courteously as he can. Columbo bobs his head and apologises for interrupting his- uh, his schoolwork?
There are no school books open on the desk, despite the fact that Light is holding a pen. Columbo asks about it and Light stumbles out a "oh, sorry Lieutenant. I just like to hold a pen when I'm thinking"
The remainder of the conversation goes as thus:
Columbo: "Oh! I do that too sometimes - always thinkin' about things at the desk, y'know, always ponderin' even when I've got nothin' to write - but, hey, kid, just make sure the pen cap's still on; don't want to dry out your nice school pen and all."
Light [glancing at the, indeed, uncapped pen in his hand]: "Ah, yes... I see. Thank you, officer."
Columbo: "It's Lieutenant, Mr Yagami-san"
Light: "Just Light is fine"
Columbo: "Of course, Mr Light-san."
Light: "No, you don't need the double honorific! If you absolutely have to, just say either Mr Light or Light-san. Not both. Got it?"
Columbo: "Oh, my apologies Mr Yagami-san, I'm still learning the language, see. Old friend of mine, uh, Jerry?" [We hear a quiet thud] "Now he's the languages guy - you'd love him, he's just as picky about getting the grammar right, and he did tell me to practice more before I got here, but.. Ah well. Guess I hafta learn on the job now, and with your help, Mr Yagami-san. Sorry, I mean, Mr Light-san."
Light [eyebrow twitching]: "Is there anything else you needed, Lieutenant?"
Columbo: "Uh... no, that's about it. I'll be seeing you around then!"
[He leaves through the door]
Light [internally monologuing]: What a noxious idiot. He almost caught me red-handed, completely by accident! And that stupid misuse of honorifics! He addresses my dad just fine, but suddenly when it's a normal name without a set title he struggles? Eugh. And now with all that time wasted, I have to write down that criminal's name all over again-- [he takes out the notebook as he hears a set of footsteps go down the stairs]
Columbo: "Oh, but there is just one more thing-"
Light [frozen in the act of just about starting to pull the Death Note out from his hidden drawer, slowly turns towards Columbo]
Columbo: "Y'see, one thing sorta stuck out to me in this whole Kira case. First, we find out Kira's killing like he's a high school student, then he changes that as soon as we learn about it. We start thinkin' he's maybe trying to frame your family, and suddenly it looks like he's trying to frame your family. I borrow the only pen in your desk's stationery cup, and Kira's next kill is delayed by about the amount of time it would take you to get up and grab a new pen, then make sure the ink is flowing."
Light: Is that why he took my pen? The bastard, he had me fooled with that idiot bumbling routine! "But, Lieutenant, how could I be killing people? I'm not some kind of supervillain with magic powers, you know - clearly it could also be that Kira is having the house watched, and is making it look like I'm to blame!"
Columbo: "Now, of course, I thought about that myself too. How could an ordinary teenager be killing scores of people from the comfort of his room? Well, see, I took a look at that very same drawer you're reaching into. And you know what I found?"
Light [face settling into a mask of calm as sweat beads on his forehead]: "..."
Columbo [smiling amicably]: "..."
Light [teeth gritted]: "...what did you find, Lieutenant?"
Columbo: "Well it's the damnedest thing, I found nothing at all... In the main part of the drawer, that is! See, I don't know if you know this Mr Yagami-san, but you've got yourself a secret compartment in that desk of yours - and inside that compartment is a notebook titled 'Death Note', in which, funnily enough, I found the exact names and methods of death for all of Kira's victims - some'a them we didn't even know were Kira's until I went and checked the information with the coroners on the other side of the country, and whaddya know? It's accurate!"
Light [more tired by the second]: "..."
Columbo: "Now, I still had no idea how you did all those killings, or even if it was you - but you'll note there was a Blanchard Moss who died while you were at school? I sent a photograph of his note in your notebook to the Columbus Division of Police, about an hour before he died - and they say it's eerily accurate. Some might even say prophetic."
Light [quietly]: "You still don't have sufficient evidence to prove it was definitely me."
Columbo: "Yeah, well, it's not like that's ever stopped Dave Columbo from taking in a suspect"
Light [suddenly smooth]: YES! I've got him! "Alright Mr Columbo-san, I'll come along with you."
Columbo [turns around.]
[As he does so, Light scribbles the name Dave Columbo into his notebook, quickly jotting down a cause of death being 'fall down stairs']
Light [stepping out of his room with Columbo]: "You're very frustrating, Lieutenant."
Columbo [turning to look at Light]: "Why thank you, Mr Yagami-san. I'll take that as a compliment."
[He waits a few seconds to see if Light will say more-]
Light [stunned, walking down the stairs]: why hasn't it worked...? He gave me a fake name, damn him! How do I get rid of the evidence? Uh... Oh! There's a refuse bin just outside the house - and it gets collected today! If I just tear out this page and throw it away, he'll look like a paranoid old man, and I-
Soichiro Yagami, captain of the Kira Task Force [takes the Death Note smoothly out of his son's hand, and passes it to Columbo]
Ryuk, now visible to most people in the room: "Oh they GOT got your ass. That's incredible, 10/10. Hey Lieutenant, you wouldn't maybe... have an apple on ya?"
Columbo [slowly drawing a slightly-battered apple from his even more battered coat pocket in intense surprise]: "Well, as it happens... I do."
Soichiro [maintaining the best composure he can while handcuffing his son]: "Light Yagami, you're under arrest on suspicion of mass murder, serial murder, and incitement to suicide, under the name 'Kira'."
if you wretched individuals reblog my post with some stuck in 2012 fuck shit about c*stiel you are certain to [experience great joy] on September 6, 2032