| Jason |
Andrews | Mudflats member; Sean's friend. Aka: Stretch. |
| Pete |
Burnette | Ken's sponsor. |
| Armando |
Cabrera | Construction worker. |
| Robert |
Donohue | Sheriff. |
| John |
Dupree | Member of the couple swap party. |
| Mary |
Dupree | John Dupree's wife. |
| Susan |
Early | Tim Early's current wife. |
| Tim |
Early | Aaron's friend. |
| Dorothy |
Farmer | The Russos' next-door neighbor. |
| Javier |
Garcia | The youngest detective. Aka: Jay. |
| Aaron |
Goldberg | Theresa Goldberg's husband. |
| Theresa |
Goldberg | Murdered 38 years ago. |
| Billy |
Green | Sean's friend; Charlie's superior. |
| Bernard |
Henderson | Former forensic pathologist. Aka: Doc. |
| Deputy |
Hicks | Crime scene technician. |
| Joshua |
Jefferson | Tyler's brother; suspect. |
| Tyler |
Jefferson | Suspect in Theresa's killing. |
| Marvin |
Johnson | Retired District Attorney. Aka: Beagle. |
| Elizabeth |
Jones | Tim's first wife. Aka: Lizzy. |
| Debbie |
Keller | Nancy's friend; found the body. |
| Jeff |
Keller | Debbie Keller's husband. |
| Jerry |
Larson | Resident. |
| Beth |
Laughlin | George Laughlin's wife. |
| George |
Laughlin | Sean's friend. |
| Frank |
Martin | Retired NYPD detective. |
| Jane |
May | Charlie's old friend; policewoman. |
| Roger |
Medcalf | Charlie's ex-husband. |
| Jackie |
Mitro | Ray Mitro's wife. |
| Ray |
Mitro | CrossFit gym co-owner. |
| Boyd |
Moretti | Partner of Charlie's father. |
| Abigail |
Nash | Charlie's mother. |
| Charlotte |
Nash | Detective Sergeant. Aka: Charlie. |
| Henry |
Nash | Charlie's father. |
| James |
Nash | Charlie's brother. |
| Spencer |
Nash | Charlie's son. |
| Sandra |
Nowak | Steve Nowak's wife. |
| Steve |
Nowak | Aaron's friend. |
| John |
O'Shea | Retired Boston detective. Aka: Irish. |
| Darryl |
Pickett | Charlie's co-detective. |
| Ken |
Russo | Sean's neighbor. |
| Nancy |
Russo | Ken Russo's wife; murdered. |
| Trevor |
Russo | Ken and Nancy's grandson. |
| Ken |
Russo Junior | Nancy and Ken's son; Trevor's father. |
| Denise |
Sheppard | Retired FBI agent; Mudflats member. Aka: Feebee. |
| Marge |
Strozewski | Witness. |
| Carson |
Tanner | Sean's son. |
| Lauren |
Tanner | Sean's wife; recently deceased. |
| Rachel |
Tanner | Sean's daughter. |
| Sean |
Tanner | Retired detective; protagonist. |
| Clinton Cannon |
The Third | Commander of the Criminal Investigation Division; Darryl's cousin. |
| Sherman |
Todd | Retired detective. |
| Dana |
Whittle | Resident. |
| Annie |
| Sean's dog. |
| Bert |
| Villager. |
| Cindy |
| Madison's mother. |
| Dave |
| George Laughlin's friend. |
| Dick |
| Marge's husband. |
| Fred |
| Villager. |
| Gladys |
| Detective division administrator. |
| Glenn |
| President of the homeowners' association in Tim's neighborhood. |
| Gwen |
| Bubba's waitress. Aka: Bubbette. |
| Jose |
| Armando's crew boss. |
| Lexi |
| Charlie's cat. |
| Madison |
| Spencer's girlfriend. |
| Mark |
| George Laughlin's friend. |
| Marybeth |
| Tim's housekeeper. |
| Phyllis |
| Villager. |
| Rory |
| Trevor's co-worker. |
| William |
| Owner of The Shrimp's Shack. Aka: Bubba. |
| Yvonne |
| Lauren Tanner's old friend. |
