[6] The show originally starred Shane Bourne, Nadine Garner, Daniel MacPherson, Aaron Pedersen, Damien Richardson and Noni Hazlehurst.

This custom continued throughout the remainder of the show, with Field (still credited as a guest star) notably appearing more frequently than any other main cast member.

Detective Senior Sergeant Stanley Wolfe (Shane Bourne, 70 episodes, seasons 1–5) is the operational leader of the Homicide squad.

He is seen to have a very proper nature (exemplified by his being called Stanley as opposed to Stan, although Jarvis does use the latter name), but can be extremely emotional in certain cases, usually ones concerning serial killers and children.

Claire is later arrested for drug possession and is placed in a sting operation in exchange for the charges being dropped, but is killed in the process, which deeply saddens Duncan.

In season three, Simon's mental health is questioned after he witnessed Duncan being beaten, and his ongoing issues later result in assault, corruption and murder charges being levied against him.

Although the charges are later dropped, Simon comes to realise his mental health is threatened by working in Homicide, and quits in the second episode of season four.

Added to the team in the season three premiere, Allie immediately steps on the toes of Simon, and the two share a tense relationship until his departure.

A champion runner, Allie joined the police force to escape the overbearing clutches of her mother, who has not spoken to her in years.

She began as the Superintendent of Homicide; however, in season two this position was jeopardised by corruption charges that were brought about by the brother of a former police officer who committed suicide after Waverley refused him a pension payout.

After this debacle, Waverley returned to Homicide as the Senior Sergeant in season three after Stanley went on extended leave, with her Superintendent position being filled by Terry Jarvis.

After Stanley returned to his old job, Bernice was later promoted above Jarvis to become the Commander of Crime, a position which necessitated her becoming less involved in day-to-day Homicide operations.

In the second season, Jarvis temporarily fills in for Waverley as Homicide Superintendent after her corruption charges and the death of her son, a position which he excels in, and enjoys.

When Waverley returns and Stanley takes extended leave, Jarvis assigns her as the Senior Sergeant of Homicide, keeping her job himself.

As a boss, Jarvis maintains frosty relationships with most of his team, particularly Duncan and Allie, and can be quite condescending, as exemplified by his use of the term "boys and girls" to refer to the Homicide squad.

Detective Senior Sergeant Claudia Leigh (Tasma Walton, seasons 2–4) is a psychological profiler brought in to some Homicide investigations to analyse the mentality of offenders.

In season four, her psychological manipulation of offenders backfires when she is attacked by a serial killer who tries to rape and kill her; attempts thwarted by the quick-thinking actions of Jennifer and Claudia.

Dr. Rhonda "Ronnie" Lafferty (Genevieve Morris, seasons 2–5) is a head pathologist with the city morgue whose specialisation is autopsies relating to suspicious deaths, therefore integrating her with the Homicide squad.

Ronnie is a highly competent and upstanding medical examiner, and believes that all murder victims deserve a chance at being investigated.

Sergeant Karen Hatzic (Louise Crawford, seasons 1–3) is a uniform police officer often assigned to the day-to-day duties related to Homicide investigations, such as retrieving files, guarding suspects and witnesses and coordinating canvasses and doorknocks.