Bolander and Felton are suspended for 22 weeks without pay for incidents related to activities at a police convention in Washington, DC. Howard plans to take the sergeant's exam. Pembleton and Bayliss are assigned to investigate the death of a body found at an arson

The fire investigation continues. Bayliss' back is acting up and Kellerman is paired with Pembleton. Kellerman shows Gee something, so he is offered a transfer into the department that he first rejects

A gas leak causes the detectives to evacuate the building, so they relocate to an old bank building. Lewis is paired up with Kellerman on the murder of a woman. Sergeant Howard tries to carve out a place for herself with the other detectives, but her efforts prove unpopular

The squad returns to the station. The FBI joins with the detectives to stop a ""thrill killer"" who's working his way north on I-95. Gee tries to reconcile with his daughter

Pembleton and Bayliss investigate a murder that was committed in a gay neighborhood by skinheads and the victim's sexual preference is questioned. Brodie is hired by the department to videotape the detectives' crime scenes. A voice stress analyzer is brought in for a demonstration

Technically it's not a homicide; however, Pembleton and Bayliss investigate the ""murder"" of a small boy who's the victim of a stray bullet, which makes him brain dead. The parents must choose what to do with their son. The Pope is in town

Lewis and Kellerman interview a suspect and uncover a 10-year-old crime, which is assigned to Howard and Munch. Tim lets Frank's secret about Mary's pregnancy slip out. Howard and Munch find the body from the 10-year-old murder bricked up in a wall

Jay Leno stops by the Waterfront Bar while in town visiting his cousin Mary; Munch and Bayliss don't want to bother him. A new year starts out with a clean board and Brodie begins his work taping with the detectives. A sniper takes the city hostage, threatening to and executing people every 8 hours

The sniper continues the shootings and everyone returns to duty lacking sleep. The media starts to make their presence felt. Munch begins to worry about Howard's safety, fearing she'll be wounded again

Gee is sent upstairs to see Barnfather and everyone speculates about the vacant Captain's position. Lewis and Kellerman are sent to Pennsylvania to extradite a woman back to Baltimore where she is a suspect in the murder of her husband. Munch tries to find a videotape in Brodie's pile

Lewis and Kellerman try to subdue a large man who's gone on a rampage. The large man is finally subdued and they find him digging up his mother. This case brings out some information about Meldrick's family, and he tries to see his brother, who doesn't want to see him

Continuing the investigation in New York City, Egan's wife is questioned by Frank and Tim. Just a few hours later, Egan's wife is killed and Egan's son is seen running. Kendall is taken into protective custody until he gives up the suspect's name

Russert and Munch are assigned to work a case together; they find a retired cop who was murdered near his wife's tombstone. The dead cop's son asks Lewis, whom he went to the academy with, to get involved with case. He also makes his own inquiries, which get him into a bit of trouble

Jake Rodzinski has trouble dealing with the verdict of the trial and takes justice into his own hands. Kellerman is back from a family wedding in Wisconsin picks up the case of the murder of Kenny Damon. Lewis is not allowed to know all the details of Kellerman's investigation, because of his past relationship with Rodzinski, their chief suspect

The entire squad is put on 24-hour surveillance when a mass murderer has been identified, isn't at home and doesn't know that they know. Gee debates leaving the squad in the midst of the stakeout, so he can attend his daughter's wedding in California. As the detectives rotate through shifts on the stakeout, the main topics of discussion are the homeowners and Bayliss' plans to leave the unit

A young girl is murdered, in a style similar to Adena Watson's murder. Frank demands to work the case alone as Bayliss begins to think that the two crimes might be related. Bayliss' obsession with trying to get this case solved and linked to Adena's murder causes the two of them to clash

Kellerman and Lewis (with Brodie) investigate a shooting at the New Moon motel, where everyone there has a motive for the crime. They split up and canvass the denizens of the motel; Lewis also searches for the victim's missing boot. The murder is just one of the many crimes that has occurred or is occurring at this establishment

Lewis and Kellerman's investigation of a murder in a housing project puts them at odds with a civilian-patrol group, run by the Black Muslims. Munch is excited because Stan is scheduled to come back June 1st. Russert and Munch catch a case where both the victim and shooter are dead

A prominent attorney is murdered and the murderer presents himself to Pembleton and Bayliss with a videotape that implicates him. Brodie works on increasing his self-image. Kellerman is determined to find out who's the ""lunch bandit

Lewis and Kellerman investigate a series of homicides that put them into the middle of a drug war. Kellerman suspects that Lewis is seeing someone, but he doesn't ""kiss and tell."" As the red piles up on the board Gee gets edgy

A trash-talking radio talk-show host makes a proposal to his listening audience. Lewis announces to Kellerman that he is getting married today, then he throws up. He motivates the rest of the squad to help him with the final details as he is getting married ""tonight after the shift ends

Mary gave birth to a girl named Olivia; Tim is more excited about it than Frank. Their latest case involves a multiple shooting a restaurant. Lewis is back from his honeymoon, but while working a case with Kellerman, he confesses that they have yet to consummate their marriage