Mexican authorities apprehended three migrant suspects—two Venezuelans and one Colombian—on Monday for the alleged murder of an immigration agent.

The arrest followed the discovery of the agent’s lifeless body earlier that day, approximately 30 miles south of the U.S.-Mexico border. State security and migration officials confirmed the arrest hours after the attack.

According to public security officials in northern Chihuahua state, the agent, identified as Luis Alberto Olivas García, sustained a fatal head injury and showed signs of violence.

García, a 30-year veteran of the immigration agency, was attacked at a checkpoint south of Ciudad Juárez while checking the identification of migrants.

Initial reports, citing Chihuahua security minister Jorge Armendáriz and the New York Times, suggest the agent suffered multiple wounds, possibly from a sharp object, and a head injury likely caused by a rock.

Armendáriz noted that García had been honored earlier that day for his three decades of service.

This rare act of violence against an immigration agent coincides with a surge in migrants attempting to cross into the U.S. before anticipated stricter border enforcement.

Reuters reported that hundreds of migrants waited in lines at a southern Mexico immigration office, hoping to secure safe passage to the U.S.

The U.S. experienced record-high border crossings under the Biden-Harris administration.

A key policy of a potential Trump second term would be to strengthen border security and implement a large-scale deportation program.

Reuters contributed to this report.