María Senaida Escobar Cerritos, 19, on the day she left El Salvador. She was shot dead June 14, while traveling in a truck with other migrants through Mexico. (Family photo)

Before María Senaida Escobar Cerritos left her small town in El Salvador, carrying a small green backpack and wearing new purple running shoes, she called her dad in Santa Cruz, Calif.

“We’re leaving now,” the 19-year-old told Darios Escobar Lainez on June 12. “We’ll finally be together again soon.”

Her plan was to travel to the U.S. border and apply for asylum.

Two days later, Escobar Lainez received another call — not from his daughter, but from another migrant who was traveling with her. Their truck had sped through a checkpoint in the southern state of Veracruz, the woman told him. María had been shot and killed by Mexican police.

“We knew the journey came with risks,” Escobar Lainez, 58, said this week. “But we never thought there was a chance that the Mexican police would kill my daughter.”

María’s death last Friday, and the police’s alleged use of overwhelming force against the migrants, is now the subject of two government investigations. It comes as Mexico, under President Trump’s threat to impose tariffs, is working to stop the flow of migrants to the U.S. border.

For many here, it’s proof that the Mexican security agencies tasked with that job are ill-equipped to stem the surge of Central Americans trying to reach the United States.

The attorney general of Veracruz, Jorge Winckler Ortiz, said a preliminary investigation, based on interviews with survivors and other eyewitnesses, suggests a police vehicle overtook a truck full of migrants beyond a checkpoint in the town of Agua Dulce, and men in police uniforms “opened fire.”

Roberto de Paz, one of the two Salvadoran migrants wounded in the shooting, echoed that account. Recovering in a Veracruz hospital, he said a patrol car pursued the migrants’ truck in a high-speed chase, first shooting from behind and then passing the truck and taking several shots through the windshield.

One of those bullets, he said, killed María. De Paz was shot in one hand.

He said he counted three police officers, each brandishing guns.

“After they saw her body, and they saw that we had been shot, they drove away and left us there,” de Paz said in a phone interview.

On Wednesday, Mexico’s secretary of public security, said his ministry’s investigation indicated that the migrants shot at police first. But on Thursday, the ministry reversed course, saying the migrants did not shoot at all.

“The most recent and up-to-date information available at this time suggests that there are no indications that shots were fired from the vehicle in question,” the Ministry of Public Security said in a statement. 

The agency, of which the Federal Police is a part, continues to investigate.

“The secretariat of security and citizen protection will not tolerate any violation of human rights and disapproves of any conduct that is remote from the observance of the law,” the ministry said. 

De Paz said the migrants were not armed.

“We were a group of migrants crammed in a truck,” he said. “There were no weapons.”

The checkpoint that the migrants passed in southern Veracruz state is part of the expanding enforcement infrastructure staffed largely by police and military personnel, some of them members of Mexico’s newly formed national guard. Six thousand members of the guard are being sent to southern Mexico, their deployment accelerated as part of the agreement this month between Mexico and the Trump administration.

That mission has worried human rights advocates since it was announced. Mexico’s security personnel had not been trained in immigration enforcement and now were being sent to the front lines of the country’s high-stakes effort to stop migration.

Mexican President Andrés Manuel López Obrador has tried to reconcile his promise to respect the rights of migrants with the country’s U.S.-backed crackdown. But multiple incidents in recent weeks, including María’s death, have made it clear how difficult it will be to strike that balance.

On June 10, a migrant woman from Honduras was allegedly kidnapped by federal agents. This week, Doctors Without Borders said Mexican immigration officers raided one of their mobile hospitals and detained migrants who had gone there for medical treatment. 

“We are already seeing the consequences of criminalizing migrants and asylum seekers and forcing them underground,” said Sergio Martín, the head of mission for Doctors Without Borders in Mexico.

María was killed five days after the United States and Mexico signed the pact to stop migration.

“The killing of a Salvadoran migrant woman by Mexican police is a tragic yet predictable consequence of Mexican security forces’ new role in immigration enforcement,” said Maureen Meyer, the director of the Mexico program at the Washington Office on Latin America.

The government of El Salvador said it is awaiting the results of the investigations. The Salvadoran ambassador to Mexico, Carlos Enrique Cáceres Chávez, told The Washington Post that he remains concerned about the rights of migrants traveling through Mexico to the United States.

“There are processes to enforce the laws against irregular migrants, and the authorities need to protect the rights of those migrants,” he said.

María decided to leave her home in the Salvadoran department of Cabañas for a long list of reasons, her father said. She was tired of being extorted by local criminal groups, who badgered her for money and threatened their family with violence. She was sick of trying to find a job in a place where none existed. And she missed her father.

Escobar Lainez has lived in Santa Cruz off and on for more than a decade.

“We decided together that she would come to California,” he said. “I told her, ‘There is work here.’ ” 

Through friends, Escobar Lainez helped his daughter find a smuggler that could take her to the U.S. border. He paid $4,000 for the journey.

On the day she left, she posed for a picture in a nearby plaza. She wore blue jeans and a black sweater. She looked younger than 19.

Escobar Lainez had heard that Mexico and the United States had agreed to stem the flow of migration, but it didn’t change their plans.

“We thought the worst that could happen is that she would be deported,” Escobar Lainez said.

María picked out a new outfit for her trip.

“She was nervous, but excited,” said her sister, Doris Escobar, 35. “She wanted to be with her father.”

María met up with 16 other migrants in San Salvador, the capital. They took a bus through Guatemala and crossed the border illegally into the Mexican state of Tabasco and called a telephone number provided by the smuggler.

They were directed to a large white pickup truck, a Chevrolet Avalanche, with a Mexican man in the driver’s seat.

De Paz was also on his way to reunite with family. His grandfather, Saul Antonio Gomez, is a U.S. citizen living in California.

“We crammed in,” de Paz said. “I was in the bed of the truck, under the cover. María Senaida was in the passenger seat.”

They drove for about an hour and a half, de Paz said, passing a checkpoint between the states of Tabasco and Veracruz.

“The driver didn’t stop at the checkpoint,” de Paz said. “Then I heard sirens.”

“A few minutes later, there were three gunshots,” he said. “The first one hit me in the hand.”

The truck stopped and de Paz got out. He saw María’s lifeless body. The police got back in their patrol car, he said, and drove away.

“We found a woman selling things on the side of the road and she called an ambulance,” he said.

When the municipal police arrived with the ambulance, there was no sign of the federal police officials accused of the shooting.

The other migrants fled the scene. One called Escobar Lainez to tell him about his daughter. 

“I started crying and crying,” he said. “I don’t understand how this happened. If they wanted to stop the truck, why didn’t they just shoot at the tires?”

Escobar Lainez has flown from Santa Cruz to El Salvador to receive his daughter’s body. He was living illegally in California, he said, and he knows returning to El Salvador probably means the end of his life in America, because crossing back would be difficult.

When he arrived in Cabañas, the Salvadoran consulate told him he would need to pay $3,800 to repatriate his daughter’s body.

“The Mexican police killed her, and now they are asking me to pay to get her body back,” he said.

“They could have arrested her. They could have detained her, but instead they shot her.”

Gabriela Martinez contributed to this report.