MEXICO CITY >> Mexico’s immigration head will face criminal charges in a fire that killed 40 migrants in a detention center last month, but President Andres Manuel Lopez Obrador said Wednesday that he will not dismiss the official known for his hard line on northbound migration.

Obrador’s decision to keep Francisco Lopez as head of the Mexican Immigration Institute appeared to conflict with the federal Attorney General’s Office announcement late Tuesday to charge Lopez in connection with the blaze.

That shows both some separation of powers in Mexico and the conundrum faced by the Mexican government. Lopez Obrador and his administration are struggling with U.S. pressure to slow northbound migration while the international community calls on them to treat migrants humanely and safely.

Lopez, a lawyer and criminologist, was called to take over the immigration job in June 2019 as Mexico was under pressure from the Trump administration to decrease the flow of migrants.

The Mexican immigration institute has been hit for years with repeated complaints of human-rights violations and unhealthy conditions in center for migrants, conditions including inadequate ventilation, clean water and food. There also have been numerous corruption complaints. Under Lopez, the institute took a harder line.

Calls have come from within Mexico, and from some Central American nations, not to stop the case of last month’s fire at the five low-level officials, guards and a Venezuelan migrant already facing homicide charges.

Lopez Obrador said in his daily press briefing Wednesday that Lopez had not offered his resignation, but added that he would not protect anyone who had committed a crime.

Federal prosecutors said late Tuesday that Lopez was remiss in not preventing the disaster in Ciudad Juarez despite earlier indications of problems at his agency’s detention centers. Prosecutors said that government audits had found “a pattern of irresponsibility and repeated omissions” in the immigation institute. However, charges being brought in Mexico, especially against public officials, do not always result in prison time.

On Wednesday, Lopez Obrador said that even though the Attorney General’s Office was investigating Lopez, prosecutors had revealed few details and it was not exactly clear how they would charge him.

“We are going to wait and we are going to make decisions in the (right) moment,” Lopez Obrador said.

The president defended Lopez, saying “his work is good in general; he has always had good performance,” despite “the misfortune” that happened in Juarez.

Lopez has been close to Lopez Obrador since the latter was Mexico City mayor, and Lopez has overseen a strategy to contain migrants in southern Mexico with the help of the National Guard, which has been criticized as the start of a militarization of Mexico’s immigration policy. It included placing retired or active military officers in leadership positions inside the immigration agency.

Lopez’s predecessor at the immigration institute, sociologist Tonatiuh Guillén, said the prosecutor’s decision “is a good signal, given that the expectation at first was just an investigation of those who were directly responsible.”

Guillén said, however, that keeping Lopez in his position generated an “unneccessary tension” because he should have been dismissed in order to make the case against him more straightforward.

Guillén resigned in 2019 because of his disagreement with hardening migration policy, as Washington was demanding.

Anger in Mexico initially focused on two guards who were seen fleeing the March 27 fire, without unlocking the cell door to allow the migrants to escape. But Lopez Obrador had said earlier Tuesday that they didn’t have the keys.

A video from a security camera inside the facility shows guards walking away when the fire started in late March inside the cell holding migrants without making an effort to release them.

The Attorney General’s Office said several other officers will also face charges for failing to carry out their duties, the statement said, but prosecutors did not explain what specific charges or identify the officials.

An immigration official said on Wednesday morning that Lopez had not yet been called to testify. The official asked for anonymity because was hot authorized to speak on the record.

Complaints about corruption and bad conditions at Mexico’s migrant detention facilities have never been seriously addressed: Prosecutors said that after a fire at another detention center in the Gulf coast state of Tabasco killed one person and injured 14 in 2020, the immigration agency knew there were problems that needed to be corrected, but alleged they failed to act.

The fire case could also put Lopez Obrador in a difficult position on his promise not to tolerate any corruption. Prosecutors said they are investigating a no-bid contract to the firm providing private security at the Ciudad Juarez facility. Investigators found a series of irregularities in the company’s work, but prosecutors did not specify if Lopez was involved in that contract’s approval.

One migrant allegedly set fire to foam mattresses at the detention center to protest detention conditions and what he apparently thought were plans to move or deport the migrants. Mexico has returned the bodies of 31 migrants to their home countries.