Mexican authorities said a dispute over prior dental work was a possible motive before the suspect exchanged gunfire with police in Agua Prieta.
NOGALES, Mexico — A 30-year-old Arizona man accused of killing a dentist in the Mexican border city of Nogales died two days later after opening fire on officers who were trying to arrest him in Agua Prieta, Sonora authorities said.
Authorities identified the suspect as Ernest “N,” also reported as Ernesto “N,” a U.S. citizen from Prescott, Arizona. Investigators said he was wanted in the Oct. 15 killing of 42-year-old dentist Amed de Jesús Preciado Hernández. Sonora authorities said the suspect had previously received treatment from the dentist and had returned to the office demanding immediate attention. A complaint connected to earlier dental work became one of the investigation’s possible motives.
According to the Sonora Attorney General’s Office, the dentist was unable to see the man when he arrived at the office. Investigators said the suspect became upset, waited outside and later approached Preciado Hernández after the dentist entered his vehicle. Authorities allege the man then shot the dentist repeatedly. The dentist died from his injuries. Officials have described the killing as a homicide but have not publicly released a complete evidentiary record explaining every step of the confrontation.
Investigators quickly identified Ernest as a suspect and obtained an arrest warrant, Mexican authorities said. Their search led them about 80 miles east to Agua Prieta, another Sonora border city across from Douglas, Arizona. On Oct. 17, agents with the state’s investigative police, known as AMIC, joined municipal and state officers at a home where authorities believed the suspect was staying.
Authorities said officers were met with gunfire when they attempted to serve the warrant. An AMIC agent suffered a grazing injury to the head and a municipal police officer was wounded in the left leg. Both received medical treatment and were reported out of danger. An official investigative vehicle was also damaged by gunfire during the confrontation.
Police returned fire, and Ernest died at the scene, according to the Sonora Attorney General’s Office. Authorities said officers provided first aid after the exchange but were unable to save him. Because he died before being taken into custody, the allegations connected to Preciado Hernández’s death were never adjudicated in court.
Carlos Alberto Flores, the head of Sonora’s investigative police agency, said the suspect was an American citizen and had a criminal history in the United States that included drug-related offenses. Mexican authorities said they were coordinating with U.S. consular officials because of his citizenship. The specific U.S. cases referenced by Mexican investigators were not detailed in the initial public reports.
Authorities have said a complaint about dental work was a possible motive rather than a final judicial finding. Some Mexican reports, citing investigators, said the dispute involved a dental piece that the suspect believed had been left loose after treatment. That account remains part of the prosecution theory authorities were developing before the suspect’s death and was not tested through a criminal trial.
The shooting brought together investigations in two Sonora cities separated by the Arizona-Mexico border region. Preciado Hernández was killed in Nogales on Oct. 15, while the effort to arrest the suspect ended in Agua Prieta on Oct. 17. Officials said both wounded officers survived, and authorities continued coordinating with U.S. officials following the suspect’s death.
Author note: Last updated October 22, 2026.