Diagnosis: Murder (season 5)

The investigation of a councilman's wife's murder uncovers a possible conspiracy within the police.

A judge's son, David, also a judge, has been having an affair with Allison Porter (Marisa Coughlan), the daughter of a media mogul, since she was 13. On her 18th birthday she announces to David that she is going public, saying "I'm an adult now, and you're not married, so there is no need for secrecy", whereupon he drowns her in the bathtub. Mark and Steve soon discover this, but David is subsequently murdered as well.

While investigating the death of an ecologist who had a long list of enemies, Sloan's house is threatened by a fire spreading through Malibu.

Jesse faces being fired and losing his State license because he is blamed for the death of a professional basketball star who took a lethal mixture of medications. Mark and Amanda quickly discover evidence that implicates murder, but Jesse's intent to clear his name puts him in more trouble.

Sloan and Amanda participate in the investigation of an airliner's deadly crash. Amanda's boyfriend Special Agent Ron Wagner declares he's taking over the investigation of the plane-crash and its hijack and smuggled Russian nuclear fuel rods for the FBI, but soon realizes he couldn't make anything like the necessary progress without the ingenious doctors trio and Steve. They team up for the investigation which becomes desperately urgent as there are indications that the nuclear material is used for a bomb likely to be used to cause an LA Apocalypse by surprising, personally vindictive suspect Diane, the spokesperson of the bereaved.

A TV executive's death from a second heart attack leads Sloan to uncover the fact that her nitroglycerin tablets had been replaced by sugar pills.

Jesse gets involved in a deadly web of international intrigue when he discovers his father is a secret agent being hunted, and it's soon discovered that an old case may hold the clues to catching the culprit.

In this comedy, Rachel York stars as an attractive in-your-face polymath who finds a murdered mime in her bed. She will do anything to solve that murder, including stealing Steve's badge and calling herself Lieutenant Stevie Sloane. In the end, Mark and Steve agree that "She is really something!"

A motorcross daredevil's fatal crash during the filming of a stunt turns out to be sabotage, and the list of suspects and motives quickly rise.

Sloan blames a crime lord for Steve getting hurt in a shoot-out, only to be accused of slaying the mobster. Sloan is also sentenced to death and gets to see whats it like on the other side.

Sloan comes face to face with an old enemy on death row who may have set him up, whilst Steve and A.D.A. Ellison team up to prove Sloan's innocence.

During an emergency drill at the hospital the nursing administrator is bludgeoned to death and an artist patient recovering from cancer is smothered in his bed. Halfway through the episode a subway tunnel collapses and they have a real emergency on top of the drill. Lots of activity, suspects, stars and subplots.

Sloan and Amanda are dinner guests on a rainy night of murder and intrigue that involves a mother and daughter.

A man holds a child-birth class hostage, along with Amanda, claiming that one of the expectant women used his sperm without permission. But when the doctor suspected of the malpractice is murdered, Sloan must find a way to defuse the situation whilst solving the murder.

A pair of talk-show hosts pull a ratings stunt that ends with one murdering the other. But Sloan quickly discovers someone may have set them up and discovers the cutthroat business of daytime talk shows gives him quite a few suspects.

A social butterfly plots multiple deaths at a prep school.

Sloan's investigation of a speedway crash that killed a stock-car racer takes a bizarre turn when the autopsy reveals he was dead before the crash even happened, leading him to believe the crash was a cover up.

A young patient dies in the ER due to red-tape delays involving an HMO, leading Sloan to question managed care.

Security guard Ryan Matthews (Gary Graham) shows up to identify the body of his murdered ex-wife, but it's not her. Little does the hospital know that Matthews is being blackmailed by a con artist who is holding her hostage. When the hospital is scammed and Matthews is the sole suspect, Sloan hatches a plan to expose the con man and clear Matthews name.

Note: This episode concludes a story that begins on Promised Land in "Total Security".

Jesse volunteers to elect the caterer for the annual Benefactor's Ball when a murder is committed. Little does he know just how cutthroat it can get.

Sloan believes that a serial bomber he helped condemn to death is guilty, even when there's another one after his execution.

After being fired from his job, Mark, Jesse, Amanda, Wagner and Steve go on an unauthorized investigation into the bombings in L.A. Guest Stars: Harry J. Lennix (plays F.B.I. Agent Ron Wagner), Arye Gross (plays Carter Sweeney), Stephanie Niznik (plays Catlin Sweeney), Jasper Armstrong Marsalis (plays Amanda's child C.J.), and Dennis Boutsikaris (plays D.A. Neil Burnside).