Confessions of a Murder Suspect

Confessions of a Murder Suspect follows Tandy Angel, a 16-year-old living with her wealthy family in the Dakota, an exclusive apartment building on Manhattan's Upper West Side. Tandy addresses the reader directly, promising to share her secrets while acknowledging she may be an unreliable narrator.

One night, Tandy wakes to sirens and learns that police are on their way up after a 911 call. Sergeant Capricorn Caputo and Detective Ryan Hayes arrive and push past her into her parents' bedroom, where she glimpses Malcolm and Maud Angel dead in bed, Maud's tongue blackened. Tandy does not cry or panic; her parents raised her from age two to be analytical and emotionally detached, training her to suppress feeling as part of cultivating her "extraordinary potential." The apartment doors lock automatically, the elevator requires a key, and there is no sign of a break-in. The only other people home are her fraternal twin brother Harry, her ten-year-old brother Hugo, and Samantha Peck, Maud's live-in personal assistant.

Caputo interrogates the family in the living room. None of the children show visible emotion, which he finds suspicious. Tandy privately agrees that the killer is likely in the room. She calls her uncle Peter Angel, Malcolm's younger brother, and the family attorney, Philippe Montaigne. When Matthew Angel, Tandy's 24-year-old brother and a New York Giants football star, arrives, he claims he spent the night at his girlfriend's apartment. Caputo suggests Matthew could have left, committed the murders, and returned undetected. Through interspersed "Confession" sections, Tandy reveals that Malcolm once provoked Matthew into hurling his Heisman Trophy, college football's most prestigious award, through a window and that Malcolm considered Matthew both presidential material and a sociopath.

Philippe advises the children not to speak to police without him present, and the officers depart. Uncle Peter moves into the bedroom of Katherine, the Angel children's deceased older sister. Matthew convenes a family meeting and urges unity, but Tandy insists they face the likelihood that police consider one of them the killer. The siblings begin pointing fingers: Hugo notes that Tandy had just received the last "Big Chop," the family's term for a grueling punishment. Earlier that evening, Malcolm hosted a dinner for the Bhutanese ambassador, during which Tandy deliberately insulted the guest. As punishment, her parents forced her to name every landmark in Bhutan in Dzongkha, the national language, while standing on her head for an hour.

Tandy resolves to solve the murders herself, having studied criminology since age six. She acknowledges the possibility that the killer shares her DNA, or that she herself could be responsible. She confirms valuables were untouched and there was no forced entry, ruling out robbery. She interviews neighbors: Mrs. Hauser, an elderly resident, reveals she overheard Malcolm and Maud arguing about finances; Morris Sampson, a mystery writer who published a novel with a thinly veiled portrayal of Maud as a cruel hedge-fund manager, provides no useful information; and Nathan Beale Crosby, a documentary filmmaker once rebuffed by the Angels, offers only patronizing sympathy.

When police return, Caputo confronts Tandy about deliberately omitting the ambassador's presence during her initial interview. He reveals that a bottle found in the trash room contained a trace of poison matching residue in a water glass from the parents' bedroom. Tandy faints at the news that her parents died of arsenic poisoning.

The family's psychologist, Dr. Florence Keyes, holds a group therapy session. Matthew erupts in rage. Hugo expresses guilt for not hearing the killer. Tandy surprises everyone by admitting she feels sadness and is glad to feel it, contradicting years of emotional training, and firmly ushers the stunned doctor out. Uncle Peter then produces financial records showing Malcolm diverted $1.7 million into an account in Matthew's name, implying Matthew may have killed their father over a gambling debt.

Alone in her room, Tandy realizes she forgot to take her daily pills the night her parents died. She connects this missed dose to her fainting, emotional outbursts, and uncharacteristic behavior. Malcolm always called the candy-colored pills special vitamins, but Tandy has never found matches for them in any pharmaceutical reference. She suspects they are performance-enhancing drugs responsible for each child's extraordinary abilities and convinces Harry to stop taking them.

Caputo arrests Tandy and Harry for obstructing governmental administration, citing Tandy's deliberate omission of the dinner guest and her refusal to cooperate. Matthew is cited for intimidation, Hugo is sent to Child Protective Services as a material witness, and Samantha is named a person of interest. At Central Booking, known as "The Tombs," the institutional smell triggers a suppressed memory: Tandy realizes she was once institutionalized, sent by her parents after a mysterious boy was taken from her. Philippe secures the family's release when the DA declines to pursue the charge.

Actress Tamara Gee, Matthew's girlfriend, announces on television that she is pregnant and that the baby's father is not Matthew but Malcolm, her secret lover. This gives Matthew a powerful motive for murder. Searching Samantha's room, Tandy discovers a gold locket inscribed "Sammy, love forever, Maud." Confronted, Samantha admits she and Maud were in love, adding another potential motive if Maud refused to leave Malcolm.

Using a key hidden inside a lamp that belonged to Malcolm's mother, Tandy opens a concealed door and discovers a secret laboratory. Inside are growth charts and computer files showing Malcolm regularly adjusted the children's pill formulations. He was experimenting on his own children. The siblings confront Uncle Peter at the Angel Pharmaceuticals factory, where Tandy sees pills manufactured for export to China under names like "Strong As Ox Pills." She accuses Peter of murder, but his alibi holds and he insists he loved his brother.

Tandy also uncovers hidden wireless cameras throughout the apartment. She investigates Crosby's apartment, where Hugo breaks in by crossing a ledge high above the street. Inside, Tandy finds DVDs labeled "ANGEL," recorded from the hidden cameras over several months. One disc contains footage of Malcolm and Maud's final moments: Maud tells Malcolm her pain is unbearable and that "everything is coming down." Malcolm reluctantly pours poison into her water glass, then drinks the remainder himself, to Maud's anguish. They express their love. Samantha enters moments later, and Maud asks her to take the trash down the chute, unknowingly disposing of the bottle police later recovered. Tandy calls Caputo immediately.

Throughout the investigation, drug withdrawal causes Tandy's suppressed memories to surface. She recovers fragments of a love story with James Rampling, son of Royal Rampling, the financier suing Maud. They met at a party, connected instantly, and attempted to flee toward Canada but were ambushed. Tandy saw Uncle Peter supervising the operation as James was forced into a vehicle. Her parents sent her for intensive therapy with Dr. Keyes to erase the memories, and James disappeared under mysterious circumstances.

At a small, private funeral, Philippe reveals the full truth: Maud had stage-four pancreatic cancer, incurable and diagnosed too late. The SEC had filed charges against her for insider trading and fraud. Malcolm was filing for bankruptcy and told Philippe he could not live without Maud. Their deaths were a mutual suicide. In her eulogy, Tandy says her parents were "good parents" who loved the children "in their own way." Hugo flings himself across Malcolm's coffin and declares, "I forgive you for the biggest chop ever," invoking the family's term for punishment one final time.

Days later, the siblings open the apartment windows, play loud music, and eat junk food their parents would have forbidden. They travel to Long Island and release Hugo's pygmy sharks into the open water toward the Atlantic. Tandy catalogues the mysteries that remain: the truth about Malcolm and Tamara, whether Matthew killed Tamara (he remains in jail), the pills' long-term effects, and what became of James Rampling. She declares she has found her calling as a detective.