Andy McNallyA down-to-earth girl who is somewhat overwhelmed by the big city of Toronto, and attempts to retain her idealism.
Played by: Missy Peregrym
- Action Girl: Played reasonably realistically. Expect Andy to lose as often as she wins in a fight.
- Country Mouse: Spent her childhood roaming the woods and looking for seashells on the beach with her father.
- Heroic B.S.O.D.: Suffers this at the end of episode 7 in Season 1, having killed a criminal in self-defense.
- Another when she sees a mother implied to be suffering from PTSD almost kill herself after her daughter dies.
- Only Known by Their Nickname: Her real name is Andrea, but everyone, and the official site, formally calls her as Andy.
- Her mother shows up early in Season 3 and calls her Andrea, confirming that she does have a first name. She doesn't like it, though.
- That Came Out Wrong: Has a habit of this, especially when talking to Sam
- Andy (talking about her uniform, metaphorically): I have no problems taking it off. (Beat). You know what I mean.
Dov EpsteinA witty, charming, impulsive young man.
Played by: Gregory Smith
- Beware the Nice Ones: Dov is a pretty nice guy overall, but in the Season 2 episode A Little Faith, he befriends an old drug dealing pal from his brother's life and rode around with him, then when the drug dealer went to an arranged deal, Dov loots him of all of his drugs and money. When asked about this, he mentions he played nice before "stabbing" the dealer in the back.
- Embarrassing First Name: Averted. One would think a boy named Dov would feel more self-conscious about it, but he isn't. But it turns out that in Hebrew his name means "bear".
- Awesome Mc Cool Name: His middle name is Ezekiel, which translates into "strength of God". Basically his full name is "Bear with the strength of God" Epstein.
- Survivor Guilt: After shooting a teenager, Dov is suffering from this as he had never killed someone before.
Traci NashLevel-headed and pragmatic, with more confidence than Andy and a young son. Later become a detective during Season 3.
Played by: Enuka Okuma
- Black Best Friend: Technically fulfills this role, but she is not particularly sassy and has a life of her own.
- Rank Up: Became a detective in Season 3.
Chris DiazA earnest rookie who knows the manual by heart and refuses to deviate from it.
Played by: Travis Milne
- Abusive Parents: His mother once had him stand still on a chair for three hours straight as a punishment for spilling some spaghetti on the floor. It is implied she had serious mental issues.
- Gentle Giant: As shown when he rescues a stolen puppy and takes it in until its owners are found.
Gail PeckThe ambitious, driven daughter of a family full of officers.
Played by: Charlotte Sullivan.
- Bi the Way: Begins a relationship with Holly the coroner in season 4, but doesn't put a label on it.
- Brilliant, but Lazy: Steals someone's credit without a second glance and eagerly shuffles cases to another department when possible, yet can memorize a license plate number with a glance at a speeding car.
- Defrosting Ice Queen: Traci actually calls her Frosty.
- Hidden Depths: Which she shows when someone is hurt or nearly dies.
- Heroic B.S.O.D.: Gail is suffering from the after effects of being kidnapped, even to the point of joking how she wants to be taken captured by a psychotic killer again in front of her father no less.
- Opposites Attract: Had a past history with Chris, and attracted the attention of Dov as well.
- Sugar and Ice Personality: Underneath her caustic, impassive exterior is a rather vulnerable young woman.
- Well Done Daughter Girl: She gets horrible stage fright when asked to speak in public, especially with her mother in the audience, and ends up pretending to be home sick both times.
- Feels intense pressure to be a better cop thanks to her family background. Not helped by the fact that the fellow rookies are under the impression that she uses her family connections to get along in her career.
- Woman in White: She is often wearing white, of the 'reluctant-to-get-her-hands-dirty' variety, while out of uniform.
Nick CollinsFormer soldier who served in Afghanistan for four years before becoming a cop. Once engaged to Gail and was readied to marry in Las Vegas before enlisting.
- Drowning My Sorrows: As shown in "Every Man", he had done this once a year in order to remember after one of his teammates was killed in action when he took his place. He decided to stop on the day when Andy found him drunk, saying he would do something else other then drink.
- New Old Flame: To Gail when he shows up in season 3.
- Retired Badass: Well, he is a marine after-all.
Sam SwarekUndercover cop, exposed when McNally arrested him on her first day. Takes the job as her T.O.
Played by: Ben Bass
- Badass in Distress: In the season 2 finale.
Oliver ShawGood guy all over. The most laid back of the T.O.'s. Happily married with children.
Played by: Matt Gordon
- Happily Married: Subverted in season 3, when we find out that he's been kicked of of the house by his wife after spending too much time at work.
- Until his wife allows him back inside after their daughter gotten caught up with a criminal.
- Papa Wolf: AND how. Not only was he about to kill a suspect in a case, but said suspect was someone who hooked Shaw's daughter with drugs and beat her, as well who knows what else given the rap sheet.
Noelle WilliamsOnly female T.O.. Tried for the sergeant position but got beaten by Best.
Played by: Melanie Nicholls-King
Staff Sgt. BoykoStaff Sergeant for the first half of the first season.
Played by: Aidan Devine.
- Da Chief: Formerly.
Staff Sgt. Frank BestT.O. for the first episode, is promoted to staff sergeant by the 8th one.
Played by: Lyriq Bent.
- Da Chief: Currently.
Luke CallahanHomicide detective. Got assigned to 15th division over the murder case of a rookie 3 years before the start of the series. ->Played by: Eric Johnson.
- Put on a Bus: At the start of Season 3
- The Bus Came Back: After the death of Jerry Barber in mid Season 3, he came back.
Jerry BarberDetective of the 15th. Was one of the rookies academy instructor. Nash's love interest.
Played by: Noam Jenkins.
- Chekhov's Gun: His new cellphone. After being mortally wounded, he manages to slip his cellphone into Gail, thus being able to locate her.
- Cowboy Cop: Shades of this happened in Season 3.
- My Greatest Failure: Weapons that he himself was suppose to have signed over for for destruction ended up being re-sold on the street because he allowed someone else to file the paper work while he was with his mistress.
Jo RosatiHomicide detective. Get's called from another division to help on 2x01, and chooses to stay. She has history with Luke Callahan.
- Kicked Up Stairs: Transferred to another division