A nemesis from New York shows up in Detroit, agitating Fitch; an entire family is murdered; Longford starts to reconsider his retirement.

As the detectives embark on emotional shifts in their lives, a young graffiti artist is murdered; Fitch receives shocking news from his ex-wife.

When the detectives investigate the murder of a college student, a former rival of Stone's surfaces as a possible suspect.

Mahajan and Longford are in for a few surprises when they investigate a bludgeoning; an ex-con confesses to killing two rivals; a woman from Stone's past complicates his relationship with Sanchez.

Fitch, Washington, Stone and Sanchez delve into the boxing world to investigate a woman's death. Her fiancé is preparing for a match against her ex-boyfriend and she was hiding a secret that could have thrown the fight. Longford and Mahajan are forced to face some tough ethical issues if they are to bring a resolution to the cold case they are re-examining. It seems that the victim led two lives, one with his wife and daughter and one with his married lover.

When a respected philanthropist is found dead in his car, Detective Fitch is the main suspect; three murder victims are found on a bus.

A stunned squad investigates the shooting death of an assistant prosecutor.

The squad investigates the murder of a movie star who had been filming in the city; a young homeless man is found encased in ice in a shantytown.

Two bodies are found in an abandoned shelter. Longford's father, to everyone's surprise is able to help with this investigation. Meanwhile, Fitch, Washington, Stone and Sanchez investigate the murder of a Latina.

Longford, Mahajan, Stone and Sanchez investigate the slaying of a wealthy, retired auto industry executive in his palatial home; Fitch, Washington and Lt. Mason comfort the family of an 11-year-old boy who was killed by a drive-by shooter.

A missing teen seems to have been murdered; a poker player is killed.

Stone and Sanchez, dealing with the fallout from their personal attraction, are assigned with Fitch to investigate the murder of successful executive Abigail James from Detroit's "Tech Town."

At the same time, Longford and Washington need to piece together the back story of another fresh murder case -- the lifeless body of a young drug dealer, "Toucan," is discovered in a trash bin.

A woman in an SUV is shot multiple times while hiding a 2-year-old in the back of the vehicle; a college janitor with drugs in his system is found dead.

A teenager is killed at the high school Lt. Mason's daughter attends; a prominent defense attorney's son is murdered.

The owner of a car wash is tortured and shot, and his business trashed; the investigation into a rising hip-hop star's death reveals a secret life.

When they investigate a woman's murder, Fitch, Washington, Longford and Mahajan stumble upon something much bigger; a murdered teenager is found along with his severely beaten father, a Vietnam veteran.

A local football star is murdered; an unpopular groom disappears during a boisterous wedding reception on a boat.

Detectives Washington and Fitch investigate a double homicide at a pharmacy; Longford and Mahajan try to track down the killer of an attorney who had many enemies; the investigations culminate in a high-speed pursuit.