A convicted murderer who escaped from custody in California allegedly killed a female officer while on the run. 

Cesar Hernandez, 34, was serving a life sentence at North Kern State Prison, but on December 2, he managed to escape a van he was being transported in just before his hearing at the Kern County Superior Court in Delano – about three hours outside of Los Angeles. 

Hernandez is believed to have escaped his chains by using a self-made key, punching an officer and running through an open gate before making his way  across the Mexican border to Tijuana, Sheriff Donny Youngblood told KGET in December. 

On Wednesday, he was involved in a deadly shooting where he killed Commander Abigail Esparaza Reyes. 

Reyes was part of a fugitive task force, known as the ‘Gringo Hunters,’ who are responsible for tracking down fugitives who escape from the US and cross over the border. 

After shooting Reyes, Hernandez ran again, as he was seen in surveillance footage darting down a street with no shirt on. 

He then hopped into a car and came out moments later dressed in a bright neon yellow outfit, the video, obtained by 23 ABC, showed. He has not been seen since. 

The US Marshall service has since requested assistance from Mexican authorities to apprehend Hernandez. 

Cesar Hernandez, 34, is accused of killing Commander Abigail Esparaza Reyes during a shootout on Wednesday. He escaped from North Kern State Prison on December 2 

Reyes (pictured) was part of a fugitive task force, known as the ‘Gringo Hunters,’ who are responsible for tracking down fugitives who escape from the US and cross over the border

The US Marshall service told the outlet they were not at the scene during the shooting, but arrived after when medics tended to Reyes who later succumbed to her injuries at the Tijuana Red Cross. 

It remains unclear how Hernandez managed to escape the recent murder scene, where he shot Reyes in the neck, according to Monserrat Peraza, a reporter for Punto Norte who was on site when it happened. 

‘When he shot the officer in the neck and bullets were going everywhere, that’s when other officers started to focus their attention on her to take her to the hospital. I think that’s when he decided to flee,’ she revealed. 

After the tragedy, Marina del Pilar, the governor of Baja California, a state in Mexico, paid her respects to Reyes, promising ‘her death will not go unpunished.’ 

‘I deeply regret the death of the Agent of the State Citizen Security Force, Abigail Esparza Reyes, at the time of participating in an operation to comply with an arrest warrant that is currently being carried out,’ Pilar said. 

‘Our wishes for prompt resignation are with you, Abigail’s life will be honored and her death will not go unpunished.’

The US Marshall Service echoed Pilar’s statement, telling NBC News: ‘Those who commit violence against law enforcement officers will be held accountable.’ 

Several bullet holes are seen on a building following the deadly shootout

After shooting Reyes, Hernandez ran again, as he was seen in surveillance footage darting down a street with no shirt on before changing into a neon yellow outfit 

The agency and local authorities continue to hunt for Hernandez. As of Thursday he remained on the loose. 

He’s been described as ‘dangerous,’ armed and having violent tendencies, according to a flyer released by officials. 

A $35,000 reward is being offered for information leading to Hernandez’s arrest.  

He was serving 80 years to life for first-degree murder after killing someone in 2019 just outside of Los Angeles County. 

He was set to appear in court in December after pleading no contest to manufacturing a weapon and possessing drugs in prison, per KGET.  

Reyes served as head of the Tijuana task force team for the past eight years, per The San Diego Tribune. She was also an 11-year veteran for the state police. 

In her career, she led operations that resulted in 408 arrests of fugitives from several countries who were trying to invade Baja California, officials said. 

‘Commander Esparza rose quickly through the ranks during her career and was instrumental in locating and arresting many criminals on both sides of the border,’ U.S. Consul General in Tijuana Christopher Teal said.  

‘Her tragic passing is a great loss not only to Commander Esparza’s family, but also to the U.S. diplomatic mission in Mexico, law enforcement in Baja California, and our community. 

Loved ones are seen at Reyes’ funeral service 

‘Her legacy of courage, integrity, and commitment to justice will continue to inspire those who follow in her footsteps. She gave her life in pursuit of a safer future for all, and her memory will always be remembered.’ 

David Arizmendi, a press secretary for the US Embassy in Mexico, said this unfortunate situation ‘is a testament of seriousness’ of the security issues Mexico and the US face. 

‘The terrible murder of Commander Esparza is a testament to the seriousness of the security issues that Mexico and the United States face and the importance of binational cooperation to address these threats,’ he said. 

‘Commander Esparza will be remembered as a true hero who was killed while bravely supporting binational efforts to keep our countries safe.’

DailyMail.com contacted the US Marshall Service for more information.