Yoo Ji-ho (M / 35) ➔ Inspector (Team Leader) -Green hair- (Husband of Kim Ji-min) Kim Yeon-jae (F / 33) ➔ Lieutenant (Assistant Team Leader) -Yellow hair- Oh Seung-yoon (M / 28) ➔ Sergeant -Brown hair- (Childhood friend of Kim Min-seo) [Son of Oh Jung-taek, who died in the line of duty during an organized crime investigation in 2011. Adopted at age 5 by Senior Superintendent Lee Da-hee / Calls Lee Ji-hye 'Noona' / Biological son of Kim Eun-young, 58, Deputy Commissioner] Kim Min-seo (F / 28) ➔ Sergeant -Red hair- (Childhood friend of Oh Seung-yoon) Kim Yong-chul (M / 30) ➔ Staff Sergeant Seo Ye-eun (F / 26) ➔ Officer (Childhood friend of Park Tae-sung) Lee Myeong-hak (M / 28) ➔ Sergeant Yoo Jin-hee (F / 32) ➔ Lieutenant (Squad Leader) Lee So-young (F / 28) ➔ Sergeant -Blue hair- Kim Hee-chul (M / 31) ➔ Staff Sergeant Lee Yoon-young (F / 31) ➔ Staff Sergeant Kang Ho-dong (M / 26) ➔ Officer Kim Tae-won (M / 29) ➔ Sergeant (Husband of Lee Ha-yeon) Park Ye-jin (F / 25) ➔ Officer Lee Soo-geun (M / 25) ➔ Officer

Lee Ji-hye (F / 33) ➔ Lieutenant (Unit Leader / Operational Leader) -Orange-brown hair- (Daughter of Senior Superintendent Lee Da-hee) (Called 'Aunt' by Oh Seung-yoon) Kim Hyun-woo (M / 31) ➔ Staff Sergeant -Green hair- (Husband of Seo Seung-hee) Lee Seul-i (F / 29) ➔ Sergeant -Brown hair- Yang Hyun-jong (M / 32) ➔ Lieutenant (Assistant Unit Leader) -Gold hair- Song Yeon-mi (F / 30) ➔ Staff Sergeant -Pink hair- Kang Young-tae (M / 28) ➔ Sergeant Lee Seok-hyun (M / 30) ➔ Staff Sergeant Lee Ha-yeon (F / 29) ➔ Sergeant (Wife of Kim Tae-won) Lee Jae-sung (M / 31) ➔ Staff Sergeant Ko Eun-min (F / 28) ➔ Sergeant Park Hyun-kyu (M / 28) ➔ Sergeant Lee Min-ho (M / 29) ➔ Sergeant Yoo Hyun-jin (F / 27) ➔ Sergeant Park Chul-min (M / 28) ➔ Sergeant Kim Ji-min (F / 32) ➔ Staff Sergeant (Wife of Yoo Ji-ho) Park Yong-jin (M / 27) ➔ Officer Lee Yeon-hee (F / 26) ➔ Officer Kim Yong-min (M / 26) ➔ Officer Yoon Bo-mi (F / 25) ➔ Officer Choi Tae-hoon (M / 25) ➔ Officer

Lee Young-ho (M / 41) ➔ Inspector (Cyber Team Leader) -Green hair- Park Tae-sung (M / 26) ➔ Officer (Childhood friend of Seo Ye-eun) Seo Seung-hee (F / 30) ➔ Staff Sergeant -Red hair- (Wife of Kim Hyun-woo) Lee Tae-min (M / 28) ➔ Sergeant -Yellow hair- Yoo Sung-min (M / 29) ➔ Staff Sergeant -Purple hair- Kim Jung-min (M / 25) ➔ Officer Lee Ha-na (F / 25) ➔ Officer Shin Mi-young (F / 29) ➔ Staff Sergeant Park Soo-jung (F / 28) ➔ Sergeant -Orange hair- Kim Mi-jin (F / 30) ➔ Lieutenant (Cyber Squad Leader / Assistant Team Leader)

Kang Dae-hyeop (M / 61) ➔ Commissioner General (Chief of Police / Provincial Chief) -Grey-black hair- (Remarried to Deputy Commissioner Kim Eun-young) (Senior to the late Oh Jung-taek by 3 years) Kim Eun-young (F / 58) ➔ Chief Superintendent General (Deputy Commissioner) -Brown-khaki hair- (Remarried to Commissioner Kang Dae-hyeop) (Senior to Senior Superintendent Lee Da-hee, former Narcotics Division) (Widow of Oh Jung-taek, who died in 2011; biological mother of Oh Seung-yoon, whom she gave up at age 5)] Jung Jin-woo (M / 55) ➔ Senior Superintendent (Director / Investigation Bureau Director) -Black hair, police cap- Lee Da-hee (F / 53) ➔ Senior Superintendent (Director / Public Safety Bureau or Criminal Affairs Bureau Director) -Black hair, updo- (Mother of Lee Ji-hye, 33, MIU) (Junior to Kim Eun-young, former Narcotics Division) (Foster mother of Oh Seung-yoon) Choi Hyun-bin (M / 49) ➔ Superintendent (Division Chief / Investigation or HR Division Chief) -Salt and pepper hair-