1 | Drew | Witthuhn | David's younger brother. |
| David | | Manuela's husband. |
| Manuela | | Only child of a German immigrant. |
| Ruth | | Manuela's mother. |
| Ron | Sharpe | Ruth's friend. |
| Max | Whitthuhn | Drew's father. |
| Ron | Veach | A lead detective. |
| Paul | Jessup | An investigator. |
| Horst | Rohrbeck | Manuela's father. |
| Possum | | A military trained dog. |
| Jim | White | A criminalist of Orange County Sheriff's department. |
2 | Roger | Harrington | Keith's father. |
| Patty | | A registered nurse. Keith's wife. |
| Keith | | A medical student. |
| Merideth | | Patty's friend. |
| Jay | | Patty's friend. |
| Sue | | Patty's sister. |
| Daryll | Coder | An investigator. |
3 | Patton | Oswalt | Michelle McNamara's husband. |
| Pete | King | A long-time reporter for LA Times. |
| Alice | | Michelle's daughter. |
4 | Terry | Keating | A drum teacher. |
| Cameron | | Michelle's friend. |
| Leo | | Michelle's father. Aka: Brother Leo. |
| Malachy | Dooley | A reverend. Brother Leo's friend. |
| Margo | | Michelle's older sister. |
| Mary Rita | | Michelle's sister. |
| Kathleen | | Michelle's sister. aka: Beanie. |
| Anton | | Kathleen's crush. |
| Lisa | Van | Michelle's friend. |
| Kris | | Lisa's sister. |
| Maureen | | Michelle's sister. |
| Marilyn | | A theology professor. Michelle's aunt. |
| Bob | | Michelle's brother. |
| | Ray | Michelle's first-grade teacher. |
| Danny | Olis | Michelle's first-grade classmate. |
| Kathleen | Lombardo | A rape and murder victim in Oak Park. |
| Ron | Tammen | A wrestler and bassist. |
| Tom | Olis | Danny Olis's younger brother. |
| Mike | | Danny's grade-school friend. |
| Darren | | Mike's friend. |
| Tom | McBride | A guy who lived a few doors down from the murder scene. |
5 | Sheila | | A rape victim. |
| Roy | Hazelwood | A former FBI profiler. |
| Richard | Shelby | A detective of Sacramento County Sheriff's Department. |
| Jane | Carson | A rape victim. |
| Jack | | Jane's husband. |
| Carol | Daley | A detective of Sacramento County Sheriff's Department. |
| Douglas | Moore | Was shot dead by man who had been prowling in backyard. |
| Priscilla | | Douglas's sister. |
| Mavis | Moore | Douglas's mother. |
| Dale | | Douglas's father. |
| Fiona | Williams | A rape victim. |
| Justin | | Fiona's son. |
| Phillip | | Fiona's husband. |
| Ray | Root | A lieutenant. Shelby's boss. |
6 | Claude | Snelling | A journalism professor. |
| Bill | McGowen | A Visalla police detective. |
| John | Vaughan | A detective of Visalla Police Department. |
| Richard | Sandstrom | A director of Los Angeles PD's hypnosis unit. |
| | Hanley | Donna's mother. |
| Donna | | A girl who had encountered a ski-mask intruder in backyard. |
| Glenda | | A girl who was shut while pulling her window curtain. |
| Carl | | Glenda's boyfriend. |
| Fran | Cleary | One who had a strange encounter with the man in backyard. |
| Shari | | Fran's daughter. |
| Ken | Clark | A detective. |
| Paul | Holes | A criminalist of Contra Costa County Sheriff's Office. |
7 | Luton | | A boy who brought a dead cat to his home. |
| Alec Jeffrey | | A geneticist. |
| Gerald | Parker | A prison inmate. |
| Mary | Hong | A criminalist of Orange County Crime Laboratory. |
| Song | Si | A Chinese coroner and detective. |
| Janelle | Cruz | A rape victim. |
8 | Linda | Sheen | A realtor. |
| Norm | Prato | Linda Sheen's boss. |
| Arthur | Hogue | Norm Prato's colleague. |
| Carol | Nosler | Linda Sheen's colleague. |
| Barry | Aninag | Irvine's PD officer. |
| Larry | Montgomery | A lead investigator. |
| Randy | Hill | Janelle's ex-boyfriend. |
| Martin | Gomez | Janelle's ex-boyfriend. |
| Philip | Michael | A lifeguard. |
| David | Decker | A YMCA counselor. |
| David | Thompson | Janelle's co-worker. |
| Bruce | Wendt | Janelle's boyfriend. |
| Tom | Hickel | Mike Martinez's friend. |
| Mike | Martinez | Arrested for attempted marijuana possession. |
| Jennifer | | Mike Martinez's girlfriend. Aka: Jenny |
9 | Larry | Pool | A senior investigator at Riverside County District Attorney. |
| Lyman | Smith | A murder victim. |
| Charlene | Smith | Lyman's former secretary turned as second wife. |
| Gary | Smith | Lyman's son from his first marriage. |
| Joe | Alsip | Lyman's former business partner. |
| Richard | Hanawalt | Alsip's defense attorney. |
| Gary | Adkinson | One of the lead investigator of Smith's case. |
| Russ | Harper | A detective. |
| Colleen | Cason | A columnist. |
10 | Kemo | | A protective dog. |
| Robert | Offerman | A surgeon. |
| Peter | | Dr. Offerman's friend. |
| Marlyn | Brady | Peter's wife. |
| Debra Alexandria | Manning | Dr. Offerman's girlfriend. |
11 | Debbi | Domingo | Cheri's daughter who run away from home. |
| Cheryl Grace | Smith | Murdered by an intruder in Goleta. Aka: Cheri. |
| Ellen | | Cheri's bestfriend. |
| Hank | | Ellen's husband. |
| Roger Dean | Domingo | An electronic technician. |
| David | Domingo | Cheri's son. |
| Barbara | | Cheri's aunt. |
| Gregory | Sanchez | A computer programmer. Aka: Greg. |
| Tabitha | Silver | Greg's new girlfriend. |
| Cynthia | | Tabitha's close friend. |
| Tammy | Straub | Spotted a suspicious young male gazing towards a garage. |
| Carla | | Tammy's daughter. |
| Cami | Bardo | A realtor. |
| Brett | Glasby | Well-known for his nastiness and violent temper. |
| Brian | Glasby | Brett's brother. |
| Linda | | Debbi's grandmother. |
12 | Stan | Los | An FBI agent. |
| David | Canter | A British crime psychologist. |
| O.B. | Thomas | A detective. |
13 | John | Muddock | Retired chief Contra Costa County Sheriff's Crime Lab. |
| Larry | Crompton | Detective at Contra Costa County Sheriff's Office. |
| Jim | Bevins | An investigator of Sacramento County Sheriff's Department. |
| Dave | Stockwell | Holes's colleague. |
14 | Jeff | Klapakis | A detective of Santa Barbara County Sheriff's Department. |
15 | George | Sellon | An architect. |
| Kay | | A marine biologist. |
17 | Tony | | Michelle's neighbor. |
18 | Arthur | Mijares | Trying to change the name of Mount Diablo to Mount Reagan. |
| Sid | Viscious | A bassist. |
| Nancy | | Sid's girlfriend. |
| Kathy | | A rape victim. |
| Esther | McDonald | A rape victim. |
| Pita | | A bloodhound. |
| Betsy | | A bloodhound. |
| Eli | | A bloodhound. |
| Judy | Robb | Pita's handler. |
| John | Patty | A criminalist. |
| Joseph | Eichler | A businessman. |
| Michael | Corbett | A developer. |
| Judy | Corbett | Michael corbett's wife. |
19 | Fred | Ray | A detective of Santa Barbara County Sheriff's office. |
20 | Jim | Walther | A homeless man. |
| Carl | Fabbri | A deputy at Contra Costa Sheriff. |
24 | Paul | Haynes | A lead researcher. Aka: Kid. |
| Billy | Jensen | Michelle's friend. |
| Andrew | Marquette | A witness. |
| Larry | Oswalt | Patton's father. |
| Kim | Rossmo | The Father of Modern Geographic profiling. |
| Erika | Hutchcraft | An investigator of Orange County District Attorney's Office. |
| Russ | Oase | A retired secret service agent. |
| Colleen | Fitzpatrick | A forensic genealogist. |