A witness told investigators that screenshots exposing an intimate relationship preceded an alleged threat, an overnight meeting and Carmen Lizet Puch’s death.
HERNDON, Va. — The events that Fairfax County police say ended with Carmen Lizet Puch’s killing began inside an ordinary workplace, where she and 19-year-old Alexis Antonio Cedillos-Campos were co-workers and, according to police, had an intimate relationship. Weeks after Puch was found dead near a Great Falls trail, court-document reporting added a crucial allegation: a witness said Cedillos-Campos became angry after Puch sent evidence of their relationship to his girlfriend.
The disclosure changed the public understanding of the case. Police had already accused Cedillos-Campos of repeatedly stabbing Puch and pouring gasoline on her after the two intentionally met in the early hours of Aug. 17. What remained less clear was why the meeting took place. Reports on the criminal complaint said a fellow worker told detectives that Puch had sent screenshots of the relationship to Cedillos-Campos’ girlfriend. The witness said Cedillos-Campos reacted by saying he would kill Puch. Police documents cited in local reporting then traced his movements from the restaurant to a telephone call arranging the meeting and ultimately to Difficult Run Park.
The relationship itself is described narrowly in the official record available to the public. Fairfax County Police Chief Kevin Davis said Puch, 42, and Cedillos-Campos were “intimate,” and local outlets identified their shared workplace as Bitez in Herndon. Public reports do not establish how long the relationship lasted, when Cedillos-Campos’ girlfriend learned about it or what was contained in the screenshots beyond their alleged role in revealing the relationship. Those gaps are significant because the criminal complaint’s motive theory depends largely on the witness’s account rather than a complete public record of the communications among the people involved.
Investigators say activity inside the restaurant nevertheless produced evidence beyond the witness’s words. Surveillance footage, according to Davis and other police officials, showed Cedillos-Campos taking a fixed-blade knife from the workplace, black latex gloves and a water bottle. Authorities said he later used the bottle to carry gasoline taken from his motorcycle. Police have portrayed the combination of those actions as preparation for the encounter with Puch. Davis said the circumstances appeared premeditated, although Cedillos-Campos was initially charged with second-degree murder and no later change to that charge could be confirmed from the reliable sources reviewed for this article.
The restaurant also served as the setting for a key telephone call. The witness told investigators that at about 1:30 a.m., Cedillos-Campos and Puch spoke and arranged to meet. FOX 5 reported that investigators obtained call records consistent with that early-morning contact. The available reports do not state that the conversation was recorded or reveal its full content, making it important to separate the existence of the call from the witness’s description of what was discussed. Police say the meeting that followed took the pair from the workplace context in Herndon to the parking area for Difficult Run Park in Great Falls.
There, according to Fairfax County police, Puch was attacked. Authorities allege that Cedillos-Campos stabbed her multiple times and poured gasoline on her before unsuccessfully attempting to ignite it. Police later said gasoline had been poured on Puch, while reporting based on police documents said investigators found black latex gloves and an empty water bottle that smelled of gasoline. A preliminary autopsy cited in local reports determined that Puch died from multiple sharp-force injuries and classified her death as a homicide. Those findings are part of the evidence supporting the prosecution’s case, but guilt has not been established by a trial verdict.
The witness’s role in the investigation did not end with the alleged threat or the early-morning phone call. According to the complaint, the witness said Cedillos-Campos called again at roughly 4 a.m. and said “he did it” before hanging up. The witness interpreted the statement as meaning he had killed Puch. It is a short phrase carrying substantial weight in the police narrative because it allegedly places Cedillos-Campos discussing the result of the encounter before anyone had publicly reported Puch’s death. As with the alleged threat, however, the statement comes through a witness account and would be subject to evidentiary scrutiny in court.
Puch was not found until later that morning. Fairfax County police said officers responded at 6:43 a.m. to a report of an unconscious woman in the Difficult Run Park parking lot in the 8800 block of Georgetown Pike. They found Puch near a 2011 Honda Civic registered to her. She was pronounced dead at the scene. Local reports said a morning runner discovered her. The first police announcement described an active homicide investigation but did not publicly connect the death to the Herndon restaurant, Cedillos-Campos or the intimate relationship.
Detectives worked backward from that scene. Investigators processed Puch’s car and the parking area, reviewed footage, interviewed witnesses and examined communications. By Aug. 19, police said they had identified Cedillos-Campos and located him in Lanham, Maryland. Fairfax County’s Fugitive Tracking and Apprehension Team worked with Prince George’s County police and the U.S. Marshals Service to take him into custody. He was held in Maryland while awaiting transfer to Fairfax County, where authorities said he faced second-degree murder in Puch’s death.
The arrest produced another major allegation. Davis told reporters that Cedillos-Campos was speaking to detectives and offering what the police chief characterized as a full confession. Authorities did not release the full interrogation in the reports reviewed for this article. That matters because a police account of a suspect’s statement is not the same as a guilty plea, and the admissibility, meaning and context of any confession can become contested issues in criminal proceedings. The publicly available reporting reviewed through Oct. 19 did not establish whether Cedillos-Campos has challenged the statement or formally entered a plea.
For investigators, the case therefore contains two related trails: one digital and one physical. The digital trail includes the alleged screenshots, telephone contacts and call records. The physical trail includes workplace video, the knife police say Cedillos-Campos took, gloves and a bottle associated with gasoline. The witness account links those categories by describing his reaction to the screenshots, an alleged threat, the call arranging a meeting and his later statement that “he did it.” Prosecutors would still have to establish which evidence is admissible and prove beyond a reasonable doubt that it supports each element of the charged offense.
The intimate relationship and screenshots may attract attention because they offer a straightforward possible motive, but they are not the only facts that define the case. Puch was a 42-year-old mother from Reston whose young daughter lost her parent. Police described her as a loving mother and assigned victim-services personnel to assist the family. Framing her death only as the end of an affair would reduce a homicide and a family’s loss to the alleged grievance described by the accused man’s co-worker. The screenshots are relevant because investigators cite them as part of the sequence of events, not because they explain or justify the violence alleged by police.
As of the latest verified reporting reviewed for this article, Cedillos-Campos remained publicly identified as the defendant charged with second-degree murder in Puch’s death. No trial outcome or final disposition was established in those sources through Oct. 19. The alleged motive, witness statements and police account of Cedillos-Campos’ confession remain prosecution evidence and allegations unless and until they are resolved through the court process.
Author note: Last updated October 19, 2026.