Sirens

Jessie Jaworski, a Pittsburgh police rookie, struggles to deal with her husband's murder.

Internal Affairs investigates missing guns from the police property room linking the thefts to the murder of Jessie's husband. Lynn battles her ex-husband for custody.

Lynn shoots a young robbery suspect in self-defense and is then stalked by the dead girl's friend; Molly botches an arrest and then gets accused of sexual harassment by her suspect; Jessie finds an abandoned baby in the car and becomes attached to him.

Lynn and Amy attempt to keep order in a neighborhood that is torn by feuding Serbians and Croatians. Meanwhile Molly must deal with her grandfather, a former police chief suffering from mental deterioration.

A deranged murder suspect causes trouble for Whelan and Stiles while transporting him from the countryside. Meanwhile, Amy and Lynn must deal an old con-man, while Jessie is chosen to represent the police on a talk radio show.

Jessie and Dan look into the mysterious death of a city councilman, while Molly goes undercover as a phone sex operator to uncover a killer.

Lynn is stabbed with a drug addict's used needle while attempting to arrest him. Meanwhile, Jessie investigates a man who claims he fired the shot that killed John F. Kennedy.

Molly's dream day off turns into a nightmare when she becomes a hostage in a coffee shop. Amy and Lynn are accused of using excess violence in arresting a traffic violator.

A student is shot while Jessie is giving a talk at her old high school, which leads to the exposure of a secret club. Meanwhile, a mad bomber makes life more difficult for the officers at the station house.

Molly is in a quandary when she accidentally learns that a fellow male officer was involved with a male murder victim; Jessie and Dan investigate a possible child abuse case.

Lynn reaches out to a teenage girl who witnessed a murder but is reluctant to testify; Richie and Molly try to stop an extortionist; Richie goes after a gangbanger.

Richie goes missing while pursuing a drug dealer; Jessie is assigned to work with the FBI and becomes close to an agent, which causes Dan to become jealous.

Molly and Lynn have to put their vacation on hold when they are assigned to protect a socialite who was a witness to a viscous drug-related murder, and is now a target of the killer.

Springer is partnered with his former training officer during a drug investigation. Lynn and Amy are assigned to protect a rapist who has just been released from prison.

Molly discovers that her new boyfriend is a gambler with mounting debts who may also be tied to a recent murder.

Buddy and Dan are abducted and kept in an abandoned warehouse by a trio of desperate robbers.

When an upstanding family man is beaten to death, an investigation leads to the dead man's brother and his ties to organized crime.

While stopping a fight between two gangs, Lynn discovers that her cousin's son is a gang member.

Springer, Molly and Richie go undercover as cab drivers to catch a serial killer targeting cabbies.

Jessie begins dating a doctor she saved during a robbery, but when she decides to break it off, he becomes obsessed and begins stalking her.

Lynn becomes involved in a racially charged case and becomes the subject of a reporter's TV profile; Molly investigates a car that has plunged into the river.

Molly goes undercover to trap a killer that is preying on homeless people at a campground. Meanwhile, Lynn befriends a deaf man who might be a witness to the killings.