Mexican authorities have arrested the head of migration for the state of Chihuahua in connection with a fire which killed 40 people at a government-run detention facility in the northern border city of Ciudad Juárez last month. The death of the migrants sparked outrage across Mexico after surveillance footage showed that officials failed to unlock the doors of the holding cell where migrants were trapped. The arrest of the director, Salvador González Guerrero, a retired Marine rear admiral, is the most high-profile arrest so far in the investigation into the cause of death of the migrants. Last week, the office of Mexico’s attorney general announced the director of the National Migration Institute (INM) is also under investigation. But the case of the fire in the Ciudad Juárez facility is not the only one. In 2020, a Guatemalan migrant died in a detention center in the state of Tabasco after migrants trapped there protested their arrest by starting a fire in the building. Fourteen others were hospitalized due to smoke inhalation. A Mexican news outlet found at least 12 fires have broken out in government-run migrant centers since 2019. The INM has long been accused of human rights abuses against migrants traveling north through Mexico to the US, including, in the past four years, reports to Mexico’s National Human Rights Commission (CNDH) of sexual assault, torture and cruel treatment, according to records from the institution. A spokesperson at the INM declined to comment for this story. In 2019, the CNDH said that migration officials tortured a Honduran migrant and threatened to disappear him. In 2021, Mexican immigration agents were caught on video throwing a migrant to the ground and kicking him in the face. Earlier this year, the CNDH denounced migration officials after they handcuffed a Salvadoran migrant to his bed for five days as punishment for launching a hunger strike. The increase in human rights abuses comes as the military has increasingly gotten involved in immigration-related tasks. After the Chihuahua blaze, Mexico’s president, Andrés Manuel López Obrador, said one of the detainees had set fire to a mattress in protest at his impending deportation. But when the fire spread, the president said officials were unable to release the migrants because the person with keys to the cell was not present. Under López Obrador, the INM has increased the number of retired military officials who oversee migrant holding facilities in Mexico, according to a report published last year by the Mexico-based human rights nonprofit Foundation for Justice. Nineteen out of 32 Mexican facilities were directed by retired military officers, the report states. And with that have come more human rights abuses in government-run migrant centers, according to Ana Lorena Delgadillo, director of the organization. “This took a radical turn when López Obrador decided to militarize migration enforcement,” she said. The reports of human rights abuses come as López Obrador, under pressure from the US, ramped up enforcement efforts to stop migrants from traveling through Mexico to the southern US border. Since the beginning of his administration, the president – popularly known as Amlo – has repeatedly overseen the deployment of the country’s national guard to join immigration officials in breaking up caravans of migrants arriving across the country’s southern border with Guatemala. And late last year the national guard and police broke up a camp of migrants along the Río Grande, in Ciudad Juárez, where they were waiting to cross into the US. “The root of much of what is happening is a result of migration policies that the United States has put in place and that Mexico has decided to accept,” Delgadillo said.