Prosecutors say notebooks found after the arrests described additional targets, stolen ammunition and a fight over the defendants’ mother’s home.

CERRITOS, Calif. — A brother and sister accused of killing a 66-year-old man while trying to take his SUV had also discussed killing relatives and a neighbor as part of a dispute over money and property, according to testimony presented in court.

John Chong Moon, 55, and Cindy Kim, 59, face murder, attempted robbery and conspiracy charges in the death of Cuauhtemoc Garcia. Prosecutors say Garcia was shot Feb. 25, 2025, near Don Knabe Community Regional Park after refusing to surrender his vehicle keys. Evidence disclosed at a preliminary hearing has widened the case beyond the shooting, revealing writings that investigators say describe plans to attack the defendants’ older sister, her family and one of their mother’s neighbors.

Garcia had driven his Toyota 4Runner to an area near the Coyote Creek Bike Path at about 12:30 p.m., authorities said. He was preparing for a walk behind a residential area near Briarwood Street when Moon and Kim allegedly approached him. Investigators said the siblings had been looking for a Honda Pilot or Toyota 4Runner because they were living in a Toyota Prius and wanted more room to sleep. They followed Garcia after he left the SUV, according to prosecutors, and demanded his keys at gunpoint. Garcia refused. Moon then allegedly shot him. A witness later reported seeing two people move Garcia’s body toward a dirt embankment. The defendants did not obtain the vehicle, and investigators began collecting surveillance footage from the park and surrounding streets.

The public case initially centered on an attempted vehicle theft that ended in homicide. It took on a broader meaning after Los Angeles County sheriff’s detectives searched the Prius associated with Moon and Kim. Detective Yoon Nam testified that investigators recovered several notebooks containing entries written by both defendants. The writings described resentment toward family members, financial hardship and efforts to obtain their mother’s property, Nam said. One entry attributed to Moon said he and Kim struggled to pay rent while their mother lived in comfort. Another described the house as their remaining source of wealth and discussed pressuring their mother to sell it “by any means necessary.” Prosecutors have presented the notebooks as evidence of planning, but the writings have not been tested before a jury. Neither defendant has been convicted, and the accusations against them remain allegations.

Some entries went beyond complaints about housing and money, according to the hearing testimony. Kim allegedly wrote in November 2024 that a firearm was supposed to be ordered to “take down” members of the family. A December entry stated that bullets had been stolen from a sporting goods business. Prosecutors also highlighted a brief note dated the day Garcia was killed that referred to a “dirty deed” in Cerritos and mentioned Bloomfield Avenue. Investigators believe the wording connects the notebooks to the shooting location. The notebooks reportedly named the siblings’ older sister, her household and a neighbor who lived near their mother. Authorities have not said that attacks were attempted against those people. They also have not publicly detailed whether a specific date, route or complete operational plan appeared in the writings.

The family conflict described in court had developed over several years. The older sister testified that she obtained restraining orders in 2016 and 2022 to protect their mother from Moon and Kim. She accused the younger siblings of taking advantage of the mother and interfering with control of her home. According to the sister’s testimony, Moon and Kim forged their mother’s signature on a deed-transfer document that appeared to give them ownership rights. Moon then allegedly advertised the house for sale on Craigslist. Those claims are part of the background presented by prosecutors and are separate from the charges involving Garcia’s death. The court record described in news accounts does not establish whether the alleged deed was recorded, whether a sale advanced or whether either defendant was charged with a property-related offense.

Detectives connected Moon and Kim to the Cerritos investigation through a combination of surveillance images, witness information and an unusual social media lead. The Sheriff’s Department released images of two people seen near the park and asked the public to help identify them. An anonymous tipster reportedly recognized the pair from a widely shared TikTok video recorded at a Panera Bread restaurant days before the shooting. The video showed a man and woman directing racial slurs at customers during a confrontation. Investigators compared the people in that recording with the park footage and focused on Moon and Kim. Authorities arrested them March 9, 2025, after a police pursuit. The viral clip did not record the Cerritos killing, but prosecutors say it helped detectives place names on two unidentified figures seen in the investigation.

Moon and Kim were originally charged with murder and attempted second-degree robbery. Later court reporting listed conspiracy to commit murder among the counts they face. Moon also faces allegations of evading a peace officer and two misdemeanor firearm violations. Prosecutors initially recommended bail of $3 million for Moon and $2 million for Kim, while later reports said both were being held without bail. The precise custody orders and the full wording of the current charging document will control as the case moves forward. A preliminary hearing does not decide guilt. Its purpose is to determine whether prosecutors have presented enough evidence for a defendant to stand trial on the charged offenses.

Moon’s attorney has pointed to what he described as a range of medical and mental health conditions. The lawyer also said Moon told undercover officers that he had been in the wrong place at the wrong time. That position conflicts with the prosecution account, which places both siblings near Garcia before and after the shooting and treats the notebooks as evidence of preparation and motive. Public reporting has not detailed Kim’s defense to the newest allegations. It also remains unclear which defendant prosecutors say supplied the firearm, when it was obtained and whether testing conclusively linked a recovered weapon to the bullet that killed Garcia. Those questions may become central if the case reaches trial.

Garcia’s death remains the only completed killing charged in the case. Authorities have described him as a Cerritos businessman who had gone to the bike path for a routine walk. Nothing in the allegations indicates that he knew Moon or Kim before the encounter. Prosecutors say he was selected because his 4Runner matched the type of larger vehicle the siblings wanted. The chance meeting separated the charged homicide from the long-running family dispute, yet investigators argue that the same pressures appear in both parts of the case: unstable housing, resentment over property and a willingness to use violence to improve the defendants’ situation.

The court will eventually have to separate writings that express anger from evidence proving criminal agreement and intent. Conspiracy charges generally require more than hostile thoughts. Prosecutors must show an agreement to commit a crime and conduct that advanced that plan. Defense lawyers can challenge who wrote individual entries, what the words meant, whether statements were serious and whether any step was taken toward carrying them out. The attempted robbery and murder counts will depend on a different group of evidence, including video, witness accounts, forensic findings and statements attributed to the defendants. Jurors, rather than investigators or news reports, would decide how much weight each piece deserves.

The case returns to court July 22. Additional hearings are expected to address the final charges, evidence-sharing and a possible trial schedule. Moon and Kim remain in custody while the prosecution continues its case over Garcia’s death and the alleged plans found in their notebooks.

Author note: Last updated July 10, 2026.