Old Cop, Young Cop

"Agent J: [pointing at Agent K] Old and busted. Agent J: [pointing at himself] New hotness."

- Men in Black 2

A constellation of two cops or detectives, an older one and a younger one. Inevitably, the older one becomes some kind of father figure to the other. In addition to that, they are often presented as very different from each other, which may or may not result in conflict between them. Maybe the older one is experienced while the younger one is new to the job. Maybe the younger one is emotional and short-tempered while the older one is more like The Stoic. Maybe the younger one is idealistic while the older one tends more towards cynicism. Maybe it's a case of Red Oni, Blue Oni. Maybe the older one is a rationalist while the younger one tends towards more intuitive methods of investigation - or maybe the other way round. If they appear in a crime or mystery setting (and they are very unlikely to be seen elsewhere), expect them to be the main characters. Also, expect at least one of them to be personally involved in the case in one way or the other.

Subtrope of Student and Master Team. If the junior partner grows up to train an apprentice of his own, it's a Master Apprentice Chain.

Anime and Manga

 * Ikari and Maniwa from Paranoia Agent.
 * Soichiro Yagami and Touta Matsuda from Death Note, at least at the beginning of the series.
 * Tiger and Bunny does this with a slight alteration: instead of cops, they're superheroes

Comic Books

 * Sideswipe and Cheetor in Fun Publications' "The Stunti-Con Job", which is in-continuity with Transformers Animated.

Film

 * Somerset and Mills from Se7en: Former Trope Namer.
 * Connor, the "senpai" (Sean Connery) and Smith, the "kohai" (Wesley Snipes) in Rising Sun.
 * Agents K and J from Men in Black.
 * Toshiro Mifune and Takashi Shimura as detectives Murakami and Sato in Akira Kurosawa's Stray Dog.
 * If Space Police count, Obi-Wan Kenobi and Anakin Skywalker follow this one to a tee.
 * Arguably also Qui-Gon Jinn and Obi-Wan Kenobi before.
 * Malone and Ness from The Untouchables.
 * Lethal Weapon: Murtaugh and Riggs.
 * Pierre Niemans and Max Kerkerian in The Crimson Rivers.
 * Bob Hodges and Danny Mcgavin from Colors
 * Anderson and Ward, Mississippi Burning.

Literature

 * Goodman and Muldoon from R.A. Wilson's Illuminatus trilogy.
 * Felidae: Pascal and Francis..
 * Knight in Sour Armour Roslyn Forrester and Wide-Eyed Idealist Christ Cwej in the Doctor Who Virgin New Adventures novels.
 * Tony Hillerman's mysteries set on the Navajo reservation feature Joe Leaphorn (older, world-weary, atheistic) and Jim Chee (younger, more idealistic, a practicing shaman).
 * Occurs in Rivers of London with DCI Nightingale (since he is over 100 years old) being the old, refined, gentleman cop, and DC Grant as the wet behind the ears, yet inexplicably smart, sarky, and mouthy new cop.
 * World-weary veteran DI Rebus spends most of the series partnered with the younger DC (later DS) Siobhan Clarke.
 * Discworld:
 * Sam Vimes and Carrot in Guards! Guards!.
 * Also, Sam Vimes and, er, Sam Vimes in Night Watch.

Live-Action TV
"1990: Max Greevey (older cop) and Mike Logan (newbie cop). 1991: Phil Ceretta and Mike Logan. 1992: Lennie Briscoe and Mike Logan. 1995: Briscoe and Reynaldo Curtis.  1999: Briscoe and Ed Green.  . 2004: Joe Fontana and Green.  2006: Played with this time: Average-experience cop Ed Green and total newbie Nina Cassidy. Cassidy left the show after one season, and was replaced with Cyrus Lupo, a cop with some seasoning, thus breaking the Trope."
 * Despite the numerous cast changes, Law & Order managed to play this Trope straight for eighteen years:


 * Played straight since season two of Law & Order: Special Victims Unit with Munch and Fin—Though one could argue they're both seasoned veterans, Munch is noticeably older, and has probably been on the force longer.
 * Twin Peaks: Windom Earle and Dale Cooper might have been this in the times before Earle's insanity.
 * Done so often on British TV that it's probably easier to list the British cop shows which don't feature this combo at some point, but what the hell, here's just a few examples which do:
 * Dalziel and Pascoe - featuring, well, Dalziel and Pascoe
 * Inspector Morse - featuring Morse and DS Lewis
 * Lewis (aka Inspector Lewis) - featuring Lewis from the aforementioned show, now promoted to DI and partnered with DS Hathaway (Has led to speculation that in another 20 years, there will be a new show entitled "Hathaway"/"Inspector Hathaway")
 * Taggart - featuring DCI Jim Taggart, partnered with first DS Peter Livingstone and then (as the better example) DS/DI Mike Jardine (although, the show did become more of an ensemble, in later seasons)
 * The Ruth Rendell Mysteries - featuring DCI Reg Wexford and DI Mike Burden (might not be the best example, one might argue that Burden is more of a little brother than a son-like figure to Wexford)
 * Life On Mars - featuring DCI Gene Hunt and DI Sam Tyler
 * This one is a bit of a variation, as both are experienced, but in their own time periods.
 * Midsomer Murders - featuring DCI Barnaby and Sergeant Troy, Sergeant Scott and finally Constable Jones.
 * Cadfael - has a variant. The series is set in medieval times and therefore before police existed, but Cadfael is an older detective monk who has a quasi-paternal relationship with lawman Hugh Berrigar.
 * The Streets Of San Francisco (1972–77), starring Karl Malden (older cop) and Michael Douglas (younger cop).
 * Sully and Davis on Third Watch.
 * The dynamic between all the rookies and their Training Officers on Rookie Blue. Actual partnerships change from episode to episode.

Video Games

 * L.A. Noire: Cole Phelps and his partners Herschel Biggs and Rusty Galloway certainly fit the bill.