We experience first-hand the intensity of the Memphis Homicide Squad, 18 elite investigators working over 150 murders a year in one of the deadliest Bible Belt towns south of the Mason Dixon line. On a hot, misty, eerie morning the body of an unidentified white male is found dead next to a dumpster. The autopsy determines that he was killed by a blow to the head. With no witnesses and no clues, Sgt. WD Merritt faces the challenge of finding out just who this "John Doe" is, before he can find out who killed him. WD begins to canvass local homeless encampments, trying to put a name to his victim. That night there's a new mystery - a man found shot in the head in his car. A prostitute witness gives Sgt. Rick Barrom his only lead, the name of another witness - Chelle. As Rick hunts for Chelle and WD works his John Doe case, along the way we learn their philosophy for coping with the extraordinary stress of the job. We spend time with them off the job as WD takes his young son fishing, and Rick works on his amazing collection of monster movie figures. The next day brings a break in WD's case that takes him to Caruthersville, Missouri where a man has seen the sketch of the victim in a newspaper and thinks he might be a transient Vietnam Vet working the River that he recently helped. Meanwhile, Rick gets the break he's been hoping for when Chelle, fearing for her life, comes forward and names her boyfriend Bobo as the shooter. In a masterpiece of interrogation strategy Rick along with WD elicit a confession from Bobo who claims that he shot the victim mistakenly thinking that he was a person who once raped Chelle. The next morning brings WD's dumpster mystery back to square one as dental records show conclusively that his victim is not the Vietnam Vet working the River.

Episode Two begins at new tragic crime scene where a 3 year old child has been found dead under suspicious circumstances. The child's Uncle, Joseph, claims that he passed out after taking medication and being forced to run in place for wetting his pants. Bruising on the child's body suggests otherwise. Baby cases affect homicide investigators the most, and Sgt. Vennes Owens heads up the team that spends the first nights of the case interviewing Estherlitia, Joseph's wife and the child's aunt. She's a nurse who has her "head in the sand” about the abuse taking place in her own house. The next morning as Vennes waits to find out from the Coroner if the child's death was in fact murder, Sgt. WD Merritt, continues to try and identify his mysterious "John Doe" found murdered next to a dumpster. In a desperate search for clues he starts to empty out all the trash in the full dumpster. Meanwhile news comes from the child's autopsy that his death was caused by blunt trauma and is ruled a murder. Vennes, using Sgt. Queen McMahon and Sgt. Tim Helldorfer, begins a long powerful and emotional interrogation of the prime suspect, the child's Uncle Joseph, hoping to get a confession. By the end of the day Joseph has refused to confess but the medical evidence is enough to charge him with murder, meanwhile WD has struck out in finding anything useful in the dumpster. The next day brings a new case to the squad and Sgt. Queen McMahon - a young man shot to death on his bicycle in a housing project. A witness comes forward with the name of a gang member "Cello' as the suspect. It's a "smoking gun" case - now Queen just has to find Cello and sends the metro gang unit out on the hunt. Meanwhile we follow Vennes to church to pray after the burial of the three year old child abuse victim. The following morning brings a series of breaks; Queen's shooting suspect, “Cello” is known to be in his lawyers office across the street from the Squad - so three investigators head out to set up a stake-out. Meanwhile the FBI sends word that WD's victim has been identified through an exhaustive manual search of fingerprint files. WD calls the victim's sister to notify her of his murder - now he can start to work on who murdered him and why. The stake-out pays off as the investigators grab "Cello" leaving his lawyers office, and Queen is able to get a self defense confession from him. The episode ends with her talking about how "Cello" has now lost most of his life along with his victim's, and how tough it is to raise young black males safely, she heads home to hug her own son.

The final episode begins with a surprise break in Sgt. WD Merritt's Dumpster Homicide Case. An inmate in the Memphis jail has come forward saying that he shared a cell with a man who confessed to committing the murder during the course of robbing the victim. The suspect is currently in jail in Covington Kentucky from where he had recently fled parole. Now WD needs to get a confession from the suspect and heads off on the eight hour drive to Covington with Sgt. Mickey Williams. Meanwhile back in Memphis we meet Sgt. James "Fitz" Fitzpatrick a 27 year veteran of the squad, as he takes his biannual weapons requalification test. Later that evening "Fitz" catches a new case - a car-jacking turned homicide - two brothers were abducted from their used car lot, one was stuffed in the trunk of a stolen car the other shot to death. A witness who spotted the license plate of a fleeing car leads police to a suspect, a hardened criminal recently out of jail, and the surviving brother Kevin is able to ID him. The suspect however refuses to talk or give names of his two accomplices. In Kentucky, WD and Mickey meet their suspect in the dumpster homicide for the first time in jail. When he hears what they are there for he refuses to talk. Stumped as to their next move, they decide that without a confession they need a statement from someone else that the suspect told about the murder, and they head off in search of his most recent girlfriend. Fitz meanwhile has a lead on the 2nd suspect in his Carjack homicide and, after a positive ID from the victims surviving brother, he mobilizes the gang unit for the hunt. Fitz strikes out in his search, but In Kentucky WD finds his suspect's ex-girlfriend who corroborates the story of his inmate witness in the Memphis Jail - he might now have enough to charge his suspect. The next day brings a break for Fitz as his 2nd suspect has been picked up for drunk driving in Dyersburg. Fitz heads off to interview him as WD returns from Kentucky. WD gets the approval of the Attorney General’s office to charge his suspect with 2nd degree murder. He calls his victim’s sister to let her know that they have found her brothers murderer, and wraps up his three month roller coaster investigation. . Meanwhile Fitz interviews his 2nd suspect and has enough to charge him with murder. The series ends as WD goes to celebrate at a restaurant with many others from the squad who worked on his case, and Fitz heads out on a date to a Memphis Redbirds baseball game to relish solving his.