One Last Kill

One Last Kill follows Seattle homicide detective Tracy Crosswhite as she reopens a decades-old serial killer investigation entangled in political corruption and personal danger.

In November 1993, newly promoted detective Vic Fazzio is called to a motel on Seattle's Aurora Avenue, where a strangled woman's body has been found in a dumpster. His sergeant reveals this is the fourth such victim in less than a year, each bearing a carving resembling angel's wings on her left shoulder. The detail is being kept from the public.

In the present day, Tracy is the sole member of the Seattle Police Department's (SPD) Cold Case Unit. She has recently exposed a corrupt 1990s drug task force called the Last Line, an investigation that poisoned her relationship with Police Chief Marcella Weber, whom Tracy discovered took drug money. Weber orders Tracy to reopen the Route 99 serial killer cases: 13 unsolved murders of women strangled along the Aurora Avenue corridor between 1993 and 1995, all bearing the angel's wings carving. Weber needs results because the Seattle Times plans a critical anniversary series and she must justify SPD's budget before the city council. Instead of assigning Tracy's trusted colleague Faz, Weber pairs her with Captain Johnny Nolasco, Tracy's longtime antagonist who led the original failed task force. Tracy recognizes the move as a setup to blame her if the investigation fails.

Tracy reviews the cold case files alongside notes left by reporter Lisa Childress, whom Tracy found alive in a previous case after a decades-long disappearance. Childress's notes contain unpublished details about the angel's wings and suspect names, confirming a task force leak. Tracy identifies two remaining suspects: Dwight Thomas McDonnel, known to pick up prostitutes on Aurora, and Levi Bishop, convicted of domestic violence. She also discovers that Faz documented semen at the fourth victim's crime scene, meaning potential DNA evidence exists.

Tracy consults Federal Bureau of Investigation (FBI) profiler Amanda Santos, who challenges the original assumptions. Santos argues the angel's wings represent not the Angel of Death but the Angel of Justice, a biblical figure who punishes the wicked. She believes the killer was sending a message to a specific person, that his first nine victims were practice for four middle-class women he truly intended to kill, and that Tracy's high-profile role could prompt the killer to resume. Tracy also visits convicted serial killer Nabil Kotar, known as the Cowboy, who confirms the markings are a message directed at someone the killer is angry at.

Tracy interviews Augustus Cesare, who served as Moss Gunderson's assistant on the original task force and managed the tip line. Cesare confirms he created a computer disk cataloging all tips and connecting threads, which he gave to Gunderson for storage. Tracy searches all 25 evidence boxes but cannot find the disk. She and Nolasco confront Gunderson, who denies knowledge of the disk and becomes defensive about whether he followed up on key tips.

McDonnel is arrested for trying to strangle a prostitute in an Aurora motel. He denies being the Route 99 Killer and requests a lawyer. Meanwhile, a dark-orange envelope arrives at Tracy's office containing the missing disk, wiped clean of fingerprints. A private forensic lab confirms McDonnel's DNA matches a fragmented profile from the fourth victim's crime scene, though the sample is mixed with a second, unidentified source. Before Tracy can interrogate him further, McDonnel is found hanging in his basement, dead for several days. Tracy remains uneasy: Serial killer suicides are statistically rare.

Reviewing the disk, Tracy discovers that tips for all four of the killer's final victims were marked with asterisks and assigned to Gunderson. She contacts the tipsters and learns all four women worked as special assistants in former mayor Michael Edwards's administration. Tracy connects this to Childress's files and realizes Childress had been investigating the Last Line, Edwards's corruption, and the Route 99 killings as interconnected threads. Gunderson buried the connection, likely because Edwards held leverage over him regarding the Last Line drug money.

Tracy's fears are confirmed when Bonnie Parker, a 60-year-old grandmother and former Edwards special assistant, is strangled in her home with angel's wings carved on her shoulder. The murder proves McDonnel was not the killer. Nolasco confesses to Tracy that he was the task force leak who gave Childress suspect names and details about the wings, hoping her investigative skills would uncover what the task force could not.

Tracy and Nolasco have crime lab director Mike Melton run the unidentified DNA at a low stringency level, searching for familial matches. The result points to Jonathan Michael Edwards, the former mayor's son, whose DNA entered the system through a driving under the influence (DUI) arrest. The killer is Jonathan's half brother, an illegitimate son Edwards never acknowledged. Edwards refuses to cooperate when confronted. Tracy defies Weber and provides the connection to reporter Anita Childress, resulting in an article warning former special assistants their lives may be in danger. She discovers that a Lisa Childress article naming the special assistants served as the killer's target list.

Edwards's wife, Marilynn Edwards, contacts Tracy and reveals she was Lisa Childress's confidential source years earlier. She forces Edwards to cooperate. He reveals that when he was young, the family's maid, Rosenda Montemayor Alvarado, became pregnant and his father intervened. Edwards never knew whether she kept the child. Tracy and Nolasco trace Rosenda, who died in 1984, and learn her son, Michael Edward Montemayor, vanished after graduating high school. A former teacher finds Montemayor in a yearbook photo, and Nolasco recognizes the face: Augustus Cesare.

Tracy has gone to the Edwards home after Marilynn called. Inside, Cesare waits with a gun. He reveals himself as Montemayor, Edwards's illegitimate son, and confesses to all the killings. He murdered prostitutes to force SPD to form a task force, then killed Edwards's former special assistants to expose his father's exploitation of women, carving the wings as a symbol of the Angel of Justice. He planted his DNA alongside McDonnel's to create a false trail and joined the police under a fabricated identity to monitor the investigation from inside. His plan is to stage a murder-suicide, making it appear Edwards killed Tracy, Marilynn, and himself.

Nolasco races to the home, enters through the backyard where the dogs have been drugged, and shoots Cesare as Cesare turns to fire. In the aftermath, Melton confirms Cesare's DNA matches the crime scene evidence. Weber protects Edwards by ordering Melton not to process his DNA and threatens Tracy and Nolasco: If they go public, she will blame the entire original task force, including Faz, for the failure. Tracy accepts the imperfect outcome to protect her colleagues. Angela Waylon, the mother of victim Cathy Waylon, gives Tracy and Nolasco handmade pens, telling them her husband died peacefully knowing the killer was found. Tracy resolves to focus on her family and the closure the victims' families have received, even though the full truth about Edwards remains hidden.