Another show (2002-2009) in the CSIVerse from the ''Series/{{CSI}}-[[Series/LawAndOrderSpecialVictimsUnit SVU]]'' school of "let's focus on a lesser-known faction of the criminal investigation world"; this one takes a look at the FBI's missing persons unit. It's hip and gritty and hyper-edited like its contemporaries, with a similar focus on the cases rather than investigators; it sets itself apart, however, by having a more emotional interest in the cases than procedural, which is greatly helped by a top-drawer performance from Anthony [=LaPaglia=].

It should be noted that while the investigation should stop with the discovery of a body, the unit very frequently ends up investigating murders along the way as well as that of the missing person, should that scenario appear.
----
!!!This show provides examples of:

* AdultsAreUseless: Happens a lot whenever a kid disappears as the parents would prefer to deny that their kids might have been involved in something they shouldn't have.
* BottleEpisode: A great deal of the "Doppelganger" was an intense mind game interrogation scene.
** The same could be said of the episode that focuses mostly on Jack's deposition for his parental custody dispute.
* CrimeTimeSoap: Every character gets some drama at some point, but Jack Malone takes the cake. His utterly horrific personal life came to dominate the series for a time. When he's killed off [[spoiler: temporarily]], rather than being tragic it comes as more of a relief, because at least he finally has some peace.
* CrossOver: They did one with ''Series/{{CSI}}'' first where first ''CSI'' broadcast their part and then the story continued with ''Without a Trace'''s part.
* DarkAndTroubledPast: [[spoiler:[[BrokenBird Samantha]], [[RapeAsBackstory as]] [[FreudianExcuse revealed]] in Season 5]].
* DeathSeeker: Jack eventually becomes one for reasons that are obvious to any longtime viewer.
* DownerEnding: And how. Half of the time the missing end up dead.
* EagleEyeDetection: Cases are solved mostly through interrogation and clues such as things left behind at a scene.
* FanService: Elena, played by the beautiful Roselyn Sanchez, went undercover as a [[BikiniBar stripper]] in one episode.
* FlashBack: Every episode and sometimes a FlashBack within a FlashBack.
* FlashbackEffects: The ubiquitous fade-to-white.
* IAmTheNoun: In one of the later episodes, Jack's girlfriend Anne must have surgery following a miscarriage. Jack is in the waiting room and starts to get annoyed, rather loudly, that nobody has the courtesy (his words) to tell him what's going on. The nurse tells him that she'll call the police if he doesn't quiet down and he replies "I am the damn police!" She tells him that she'll see if she can get a nurse.
* InMediasRes: One of the basic foundations of the show. The story typically begins just before the disappearance and the remainder of the show is spent fleshing out the back-story through the use of flashbacks during interviews.
* InfantImmortality: Both averted and played straight. Children and teens turn up missing in quite a few episodes, and their turning up alive is ''never'' guaranteed.
* ItsPersonal
* LoveTriangle: Repeatedly, between the different members of the squad.
* MamaBear: Elena is willing to go as far as to disobey direct orders and ''hold a corrupt cop at gunpoint in his car'' to rescue her daughter Sophie.
* MissingWhiteWomanSyndrome: Noted in a number of episodes, but heavily discussed (and ultimately deconstructed) in "White Balance", which focuses on two missing teens: a black male and a white female. The disparity in media coverage is heavily featured, as well as the UnfortunateImplications of the boy suddenly getting more media attention, but only when it looks like he might be behind the girl's disappearance. Famous for its ending - [[spoiler: a NoEnding in which it's revealed only one of the teens was found alive, but not which teen.]]
* MistakenForCheating: "Midnight Sun" features as the victim Greg Pritchard, supposedly a loving family man but whom witnesses soon report having seen at a diner in the company of an attractive young woman. However, a trace on the woman's credit card reveals the truth: [[spoiler: she is a deputy U.S. Marshal, and Pritchard's handler in the Witness Protection Program.]]
* MurderDotCom: "Party Girl"
* NoEnding
* OohMeAccentsSlipping: Poppy Montgomery's accent has racked up enough frequent flyer miles over the Pacific that it will never need to buy a plane ticket again.
* PaedoHunt: A more literal application of the trope happens in one episode. A young looking woman poses as underage bait, a fledging, wheelchair bound unofficial cop (an accident prevented him from getting a badge), and a cameraman ([[RapeAsBackStory who was later revealed to have been raped during a home invasion when he was 12]]) set up a sting operation to catch pedophiles, a la ToCatchAPredator. Unlike the Chris Hanson manned operation, this version is more vigilante based and not exactly fool-proof to prevent people from escaping, which one guy managed to do. The cop goes after him and gives him a ReasonYouSuckSpeech, which drove the pedophile to [[DrivenToSuicide shoot himself with the cop's gun]]. To make things even better, when the cameraman realized the cop was about to tell the police about what happened, he tried to kill him to shut him up, though was unsuccessful. By episode's end, the cop survived the assault but by killing the cameraman.
* PerpWalk: Pretty much whenever the Missing Persons case leads to an arrest.
* ProsceniumReveal: Security guard sees suspicious car. He looks inside and sees a bomb, which explodes, setting him on fire. Turns out this security guard is actually a stuntman, participating and shooting of B-Movie. Then he walks away from the set and never comes back.
* PunnyName: Samantha "Sam" Spade, named for the hero of ''Film/TheMalteseFalcon''.
* RapeAsBackstory: [[spoiler:Samantha's sister was raped by a local man. Sam beat him to death with a shovel, and the sisters buried him in the woods]].
* RapeDiscretionShot: Seen in two episodes, both during flashback sequences. In one episode, a blind girl recounts how she and her female tutor were kidnapped by two teens, one of whom proceeded to rape the tutor while the blind girl listened with terror on her face. The other episode uses this during the revelation of [[spoiler:Samantha's]] DarkAndTroubledPast.
* SleepingWithTheBoss: Samantha Spade had a brief sexual affair with her supervisor, Jack Malone. It resulted in his marriage dissolving.
* TownWithADarkSecret: A favorite trope of the show, especially in "Our Sons and Daughters".
* VomitingCop
* WhatTheHellHero: In the Season 4 episode "White Balance," Jack gets this from both Vivian and the mother of a teenage black boy who's gone missing at the same time as a teenage white girl--the reason being that, under pressure from his superiors, Jack has [[MissingWhiteWomanSyndrome placed more emphasis on finding the girl.]] When the mother confronts him in his office, Jack tries to explain that the directives for the case are out of his hands, but she fires back:
--> '''Mother:''' Let me tell you what the real issue is here, Mr. Malone. My ''black'' son's life isn't half as important as that ''white'' girl's!
** In a later episode, Samantha brings Jack to task for doing an unauthorized background check into the past life and criminal history of her child's father, which results in the guy waiving his parental rights to the unborn child.
--> '''Jack:''' I was just trying to do what I thought was right.
--> '''Samantha:''' How long are you going to keep using that as an excuse to screw people over?