Key points:

• An escaped California inmate is now wanted for killing a Mexican police commander during a shootout.
• Officer Abigail Esparza Reyes was shot while attempting to arrest Cesar Hernandez, a convicted murderer.
• The "Gringo Hunters" unit has been active in apprehending U.S. fugitives hiding in Mexico since 2002.
• Hernandez managed to escape the scene disguised as a cleaner after the incident.
• The U.S. Marshals have expressed their condolences and pledged support in the investigation.

A Californian fugitive is now at large after allegedly shooting and killing Abigail Esparza Reyes, a leader of an elite Mexican police unit known as the "Gringo Hunters," during an attempt to apprehend him in Tijuana. Reyes, aged 33, was killed in a violent encounter on April 9 while her team was attempting to arrest Cesar Hernandez, a convicted murderer who had escaped from California custody last December, according to officials.

The elite unit focuses on tracking down U.S. fugitives who flee to Mexico, and Reyes had been at the forefront of this operation for eight years, conducting over 400 missions to detain such individuals. Following a tip-off about Hernandez's whereabouts, the unit located him in a Tijuana residence. However, as they approached, Hernandez opened fire, fatally wounding Reyes.

Initial investigation reports indicate that Hernandez, who had been serving a sentence of 80 years to life in prison for first-degree murder, managed to elude capture following the shootout. Witnesses and surveillance footage revealed that he fled the scene disguised as a sanitation worker, later changing into a fluorescent uniform, which resembles that worn by local authorities.

Reyes's death has drawn condolences from government officials, including Baja California Governor Marina del Pilar, who vowed that her sacrifice would not go unforgotten. "Abigail's life will be honored, and her death will not go unpunished," she said via social media, acknowledging the officer's dedication to her role within the state’s police force.

The gravity of this incident underscores ongoing concerns around cross-border crime and the risks faced by law enforcement in both countries. The U.S. Marshals were reportedly present during the operation and emphasized their commitment to supporting Mexican authorities in ongoing investigations. As authorities continue the manhunt for Hernandez, the implications of this gun battle echo deeply within the context of law enforcement efforts in the region.

For more details, visit ABC News, Reuters, and CBS News.