Detectives say the entries connect a fatal attempted SUV theft to months of planning against the defendants’ relatives.
BELLFLOWER, Calif. — Several notebooks found after the arrests of two siblings have transformed a Cerritos murder prosecution into a wider case involving alleged weapons planning, family targets and a campaign to gain control of their mother’s home.
The writings are expected to play a central role as prosecutors pursue charges against John Chong Moon, 55, and Cindy Kim, 59. Both are accused in the Feb. 25, 2025, death of Cuauhtemoc Garcia, who was shot after refusing to give up the keys to his Toyota 4Runner. Detective Yoon Nam testified that the notebooks also contain entries about killing the defendants’ older sister, members of her household and a neighbor of their mother.
The notebooks provide prosecutors with a written timeline that begins before Garcia’s death. An entry attributed to Kim in November 2024 referred to ordering a firearm to attack members of the family, Nam testified. A December entry said bullets had been stolen from a sporting goods store. Other passages described the defendants’ frustration with their living conditions and their mother’s control of a house. Moon allegedly wrote that he and Kim struggled to pay rent while their mother lived in comfort. He referred to the property as their remaining source of wealth and discussed pressuring her to sell. Investigators interpret the language as evidence of motive and preparation. The defense has not had a trial opportunity to challenge the complete writings, and news reports have disclosed only selected lines.
One of the most important entries was allegedly made on the day Garcia died. Kim wrote a short phrase referring to a “dirty deed,” Cerritos and Bloomfield, according to testimony. Don Knabe Community Regional Park is located along Bloomfield Avenue, near the section of the Coyote Creek Bike Path where Garcia was killed. Prosecutors are likely to argue that the note records the homicide in the defendants’ own language. Defense attorneys can question when the entry was written, whether the handwriting was reliably identified and what the phrase meant. Public accounts do not say whether ink testing, page sequencing or other forensic work established the exact time the words were placed on paper.
The writings do not stand alone. At about 12:30 p.m. on Feb. 25, Garcia drove his 4Runner to the Cerritos park and left it for a walk. Prosecutors say Moon and Kim had been searching for a larger SUV because they were living in a Prius and wanted more sleeping room. They allegedly considered a Honda Pilot or a Toyota 4Runner. After seeing Garcia’s vehicle, they followed him and demanded the keys while Moon held him at gunpoint, investigators said. Garcia refused. Moon allegedly fired the fatal shot. A witness later told detectives that two people matching the suspects’ descriptions moved Garcia’s body toward a dirt slope.
Surveillance video documented people near the park, but investigators initially needed the public’s help to identify them. The Los Angeles County Sheriff’s Department released images from the area. An anonymous person then connected the figures to a TikTok video that had spread online after a hostile encounter at a Panera Bread restaurant. The recording showed a man and woman using racial slurs against customers. Detectives concluded that the people in the restaurant footage were Moon and Kim and compared their appearance with the Cerritos images. Authorities arrested the siblings March 9, less than two weeks after the killing. The restaurant incident is not part of the charged homicide, but the video supplied the identification lead that broke open the case.
After the arrests, the notebooks gave detectives a new set of questions. Investigators had to determine who wrote each entry, whether the plans were shared, which people were referenced and whether any weapons or ammunition had been acquired for the alleged family attacks. They also examined the relationship between the writings and the defendants’ real-world conduct. A conspiracy case normally requires proof that two or more people agreed to commit a crime and that at least one participant took a step to move the plan forward. A note about obtaining a firearm or ammunition may support that theory, but prosecutors must establish that the words reflected an actual agreement rather than private fantasy, anger or exaggeration.
Moon and Kim’s older sister supplied context for the names and grievances in the notebooks. She testified that she secured restraining orders in 2016 and 2022 to protect their mother. She believed her younger siblings were taking advantage of the older woman. The sister further alleged that Moon and Kim forged the mother’s signature on a deed-transfer document and tried to assume control of the house. Moon allegedly placed the home on Craigslist in an effort to sell it. The disclosed court record does not make clear whether the deed was accepted by a government office or whether the listing led to a transaction. No separate conviction for that conduct has been reported.
Prosecutors say the older sister’s efforts made her an obstacle. The notebooks allegedly targeted her, her family and a nearby resident whose role has not been publicly explained. No attack on those people was completed. Authorities have not disclosed whether the defendants conducted surveillance, selected a date or visited a target with a weapon. Those missing details could determine how strongly the writings support conspiracy charges. If the entries contain only broad hostile statements, the defense may seek dismissal or acquittal. If other evidence shows purchases, travel, communications or coordinated assignments, the prosecution’s argument would be stronger.
Both defendants face murder, attempted robbery and conspiracy allegations. Moon is also charged with evading an officer and two misdemeanor firearm offenses. Prosecutors initially sought multimillion-dollar bail, asking for $3 million for Moon and $2 million for Kim. Subsequent reports said both were being held without bail. The charging history may be clarified in later proceedings because early announcements focused on murder and attempted robbery, while accounts of the preliminary hearing included conspiracy to commit murder. A formal information filed after the hearing should identify the counts that will move toward trial.
Moon’s attorney has said the defendant has medical and mental health conditions. The lawyer also cited a statement in which Moon allegedly told undercover officers he had simply been at the wrong place at the wrong time. That defense may require attorneys to explain why Moon appeared in relevant footage and why writings attributed to him discussed wealth, the mother’s property and coercion. Kim’s lawyer may separately challenge whether her entries prove she participated in Garcia’s killing. California law can allow accomplice liability when a defendant aids an intended robbery that results in death, but the precise theory depends on the charges and the evidence accepted by the court.
The notebooks may create evidentiary problems for both sides. Prosecutors will want jurors to read enough of the material to understand motive and planning. Defense attorneys may argue that lengthy collections of angry or unusual thoughts would produce unfair prejudice, especially if many passages do not relate directly to Garcia. A judge may have to decide whether the family and homicide allegations should remain in one trial. The court could also consider limiting instructions that tell jurors how particular entries may be used. Handwriting experts, forensic document examiners and detectives involved in the search could be called to establish authenticity.
Other evidence may reduce or increase the importance of the notebooks. Surveillance footage could establish movement through the park. Phone-location records might place the defendants near Bloomfield Avenue. Ballistics could connect a recovered firearm to Garcia’s wound. Fingerprints or DNA could link objects to one defendant rather than the other. Witness testimony could describe the confrontation and disposal of the body. Prosecutors have not publicly provided the complete forensic picture, and no jury has decided whether the evidence proves the allegations.
The writings also present a question of interpretation. People may record threats without carrying them out, while criminal plans may be written in coded or incomplete language. Jurors would have to consider the words beside conduct, timing and corroborating records. The note dated the day of the killing could be especially important because it appears close in time and place to the charged act. Earlier entries may be used to show a developing pattern, though Garcia was not part of the defendants’ family and was apparently selected for his vehicle.
Moon and Kim are scheduled to return to court July 22. The next stages are expected to define the surviving charges, settle disputes over the notebooks and set the path toward trial in Garcia’s death.
Author note: Last updated July 10, 2026.