Season 1 of the Shield premiered March 12, 2002. It gives an introduction to The Strike Team and the other characters of the Barn. Important plotlines are the aftermath of Vic's murder of Terry Crowley and Captain Aceveda's scheming to bring Vic and the Strike Team down; Dutch and Claudette's attempts at tracking down a serial killer; Julien's training under Danny and his struggle with his homosexuality; Vic's use of Rondell Robinson to control the local drug trade and the fallout; as well as the corrupt actions of Ben Gilroy.

Season 2 of the Shield television show premiered January 7, 2003. The season mostly revolves around a brutal new drug lord, Armadillo—a sadistic child rapist, who likes to set his rivals on fire using a tire necklace and gasoline—who begins to take over the drug trade in Farmington. Meanwhile, Officer Sofer is involved in a shooting of a Muslim man and has to deal with the fallout. This season is also heavily concerned with the Strike Team's plan to rip off the money train of the Armenian Mob, which ends up going down in the season finale.

Season 3 of the Shield TV series premiered March 9, 2004. The season mainly revolves around the aftermath of the Money Train Heist and its effects on the Strike Team, as the Armenian mob and also David Aceveda begins to suspect the Strike Team. In order to save the team, Lem (Curtis "Lemonhead" Lemansky) burns a majority of the money, ultimately leading to a confrontation which causes the Strike Team to split up in the season finale. The Armenian mob sends Margos Dezerian to wipe out the Strike Team. Dezerian leaves a trail of murders, resulting in his own execution at the hands of Mackey. Claudette had been promised a promotion to captain and throughout the season was in a supervising role, while Aceveda prepared to move onto city council. Near the end of the season a public defender was shot, and Wyms and Dutch discovered she had been a heavy drug user for the past 3 years. Wyms explored further and became very unpopular with the D.A. and around the Barn because she was (against orders) reopening the defender's lost cases. This resulted in her being denied her promotion to captain of the Farmington District.

Amazon.com DVD Review - With the addition of Glenn Close to its already excellent cast, The Shield entered its fourth season with tensions high and tempers flaring. Aceveda (Benito Martinez) has gained political clout on the City Council, and former Farmington district officer Monica Rawling (Close) is introduced as the new Captain of "the Barn," where she immediately confronts a maelstrom of personal and professional turmoil. His strike team now splintered, Mackey (Michael Chiklis) has returned to routine detective duty, while Shane (Walton Goggins) and new partner "Army" Renta (Michael Peña) are neck-deep in trouble with Farmington's "untouchable" drug-lord, Antwon Mitchell, a new villain played to perfection by actor/comedian Anthony Anderson. This seemingly traitorous predicament places Shane at further odds with former strike-teammates Mackie, Lemon (Kenneth Johnson) and Ronnie (David Rees Snell), and while Wyms (CCH Pounder) resents Rawling's promotion, the "Dutch" (Jay Karnes) makes a selfish backroom deal that causes further friction with Wyms and Mackey. Tensions are intensified by Rawling's aggressive seizure of homes and property paid for with drug money -- an effective campaign that forces "Danny" (Catherine Dent) and Julien (Michael Jace) and the entire police force to take sides in a hotly divisive civil rights debate that culminates in the murder of two Farmington cops.  Although some critics felt Close was too refined for a series as gritty as The Shield, she quickly found her place in the show's tight ensemble, earning an Emmy nomination (along with Pounder) and giving Mackey a formidable boss who earns his respect. And while Aceveda wrestles with psychosexual demons resulting from his humiliation in season 3, the high-stakes threat of Antwon Mitchell embroils the Barn in a cauldron of mistrust and political upheaval. More than any previous season, this 13-episode story arc is character-based and internally driven by clashing agendas. Sub-plots run the gamut of neighborhood killings and gang-banger conflict, but as always The Shield also finds room for plenty of mordant wit and tension-relieving sarcasm. Like all previous Shield DVDs, this four-disc set includes informative episode commentaries from the entire cast (including Close) engaged in revealing discussions of their creative process with creator Shawn Ryan and several primary writers and directors. Best of all, the "Under the Skin" documentary is a way-above-average, 60-minute survey of The Shield's day-to-day production, offering plenty of behind-the-scenes footage and eloquent insight about the challenge of maintaining high-quality drama during a fast-paced guerilla production schedule. It's essential viewing for Shield fans and anyone considering a career in television. --Jeff Shannon

Season 5 of the Shield television series premiered January 10, 2006. The season revolved around Internal Affairs Department Lt. Jon Kavanaugh's (played by Forest Whitaker) investigation into the Strike Team, representing one of the greatest threats the team has ever faced. As a result of Kavanaugh turning one of Vic's informants, IAD became aware of Lem stealing heroin which he never turned in. Having found the heroin, IAD is capable of arresting Lem, but Kavanaugh wants him to incriminate the whole team and has him wear a wire, which he warns the team of and they use it to embarrass IAD. Kavanaugh applying pressure to the team in any way he can, finds out about Mackay's share of the Money Train money, and ultimately arrests Lem having made a deal with Antwon Mitchell, a gang leader the team had put in prison. to put Lem in prison with him if convicted. Mackay supports Lem and gets bail, while Shane is worried he will give evidence against the team. Claudette finally gets her opportunity for promotion as the captain of the Barn, which she reluctantly accepts. The season concluded with Shane Vendrell, fooled by Aceveda that Lem was going to turn on the Strike Team, murdering his friend and fellow team member Lem with a hand grenade.

Season 6 of The Shield TV show premiered on FX on April 3, 2007. Continuing directly after season 5, Vic and the Strike Team are distraught over Lem's death. Shane has been overcome by guilt and becomes reckless and suicidal. Kavanaugh refuses to let the case die and resorts to planting evidence and coercing witnesses to lie about the Strike Team and specifically, Vic. Dutch and Claudette begin to suspect his integrity and Kavanaugh finally confesses to his actions and finds himself under arrest. Vic learns from Claudette that the Chief plans to force him into early retirement — and vows to wreak bloody vengeance on Lem's killer before losing his badge. Claudette learns that the Barn could be shut down if no improvements are made by the time quarterly crime statistics are released. The season concludes with the breakdown of Vic and Shane's friendship and Shane getting in over his head with the Armenians.

Season 6 was originally intended to be aired as the second half of Season 5 (in the same way that HBO split up the last season of The Sopranos); FX decided to refer to these ten episodes as "Season 6" instead.

Amazon.com DVD Review - For six seasons, viewers have watched self-proclaimed "different kind of cop" Victor Samuel Mackey get away with murder, corruption, and other sick and twisted crimes too numerous to mention. In the series' penultimate episode, "Possible Kill Screen," Mackey summons from the depths of his tortured soul all of his crimes and abuses as part of an immunity deal he has cut for himself with the Feds at the expense of his unwitting partner, Ronnie (David Rees Snell). Referring to his interrogator's recorder, he asks, "How much memory does that thing got?" How do you solve a problem like Vic? Do you kill him off? Send him to prison? What would be just comeuppance for a character, who, through it all, has somehow compelled our rooting interest? "You have to pay some kind of price," his ex-wife Corrine (Cathy Cahlin Ryan) wails. Suffice to say, without spoilers, that in this Emmy-worthy final season, Vic will be held accountable in a way that does his character (and the audience's investment in him) justice and leaves this groundbreaking series' proud legacy untarnished. It is an understatement when one character notes, "There is a lot of [stuff] going down at the Barn right now." To cover their tracks from the Armenian money train robbery, Vic and his guys orchestrate a gang war that quickly spins out of control. Shane (Walton Goggins), estranged from the Team, is forced to go on the run with his pregnant wife and young son. Corrine agrees to help Dutch (Jay Karnes) and Claudette (CCH Pounder) bring Vic down. As the Strike Team sinks further in the hole they've dug for themselves, viewers can take some comic relief in Det. Steve Billings' (David Marciano) pathetic attempts to defraud the city in the wake of his "injury," and solace in the solid police work of Dutch, Claudette, Danni (Catherine Dent), and Tina (Paula Garces), who is approaching the anniversary of her first year on the force. Stand-alone cases (a missing student whose mother won't cooperate with the investigation) and personal dramas (Claudette's failing health) further enrich each gripping episode, leading to an immensely satisfying series finale that fires on all cylinders. This four-disc set includes a wealth of extras, including convivial episode commentaries, deleted scenes, a genuinely moving featurette that goes behind-the-scenes of the series finale, in which Chiklis pays heartfelt tributes to the ensemble, and a season retrospective that fittingly, gives Chiklis the last word: "We know what we have. We have one of the great television series of all time on our hands." The Shield, we salute you. --Donald Liebenson