With a military intelligence official looking on and state and federal police officers in the immediate vicinity, witnesses said, the students were put into police vehicles and taken away. They have not been seen since.
They were among the 43 students who vanished in the city of Iguala one night in September 2014 amid violent, chaotic circumstances laid bare by an international panel of investigators who have been examining the matter for more than a year. The reason for the students’ abduction remains a mystery.
Despite apparent stonewalling by the Mexican government in recent months, the panel’s two reports on the case, the most recent of which was released on Sunday, provide the fullest accounting of the events surrounding the students’ disappearance, which also left six other people dead, including three students, and scores wounded.
The reports describe a night of confusion and terror for the students and city residents, and a seemingly clinical, coordinated harvest by Mexican law enforcement officials and other gunmen operating in and around Iguala, in Guerrero, one of Mexico’s poorest and most violent states.
The government said 123 people, including 73 municipal police officials, had been detained on organized-crime charges in relation to the night’s events, and the Mexican authorities have linked the Iguala police force to a powerful drug gang.
The 43 students were undergraduates at Escuela Normal Rural Raúl Isidro Burgos, a teachers college, in Ayotzinapa, with a history of activism.
They were among about 100 students who headed out on the evening of Sept. 26, 2014, with a plan to steal some buses. This was a tradition that students at the school had done for many years: They would take the buses, use them to transport their peers to an event and then return them when they were done. The bus companies and the authorities mostly tolerated it.
The plan for the outing that evening was to secure several buses to carry students to a march in Mexico City several days later to commemorate a student massacre that had occurred in 1968.
Riding in two buses they had commandeered on earlier occasions, they stationed themselves on a main road on the outskirts of Iguala, planning to intercept a few buses.
“All of us were happy, having a blast, relaxed, happy with the drivers, playing,” a student later testified, according to the panel’s first report. It relied on testimony from survivors, government security officials and other witnesses as well as reports from an interagency government command center.
But the region’s security forces were already onto the students’ plans. The federal police stepped up patrols near the buses, and the command center linking local, state and federal police forces, as well as the military, kept tabs on the students.
At 8:15 p.m., the students made their first strike, boarding a bus that had stopped in front of a restaurant. The driver knew the drill; bus companies generally instruct drivers that in the event of a student hijacking, they should remain with the buses to ensure their safe return.
The bus driver said he needed to make a pit stop at Iguala’s central bus station. At the station, the driver surprised the students and locked them in the bus.
Around 9:15 p.m., the students in the two other buses arrived at the station and freed their classmates. The group commandeered three more buses, leaving behind one that had no driver. The five buses then left for Ayotzinapa, three heading toward Iguala’s northern beltway, two toward the southern beltway.
Several police cars pursuing the three northbound buses started firing warning shots into the air. But the threat of violence did not deter the students.
A group of them left the buses and started throwing rocks at a police car that had blocked their path until the car drove away. At another point, a student sneaked up behind a police officer and tried to disarm him. As other police officers came to their colleague’s aid, the student ran away, and a police bullet ricocheted and struck him, lightly wounding him.
As the convoy resumed its northward course through the city, police bullets hit the buses. The students threw themselves flat on the floor but ordered the drivers to keep going.
Near the beltway, however, the police had blocked the road with a vehicle. Several students got off the buses and tried to lift the cruiser out of the roadway, but officers posted on the highway opened fire on the group, forcing the students to seek cover behind the buses. Investigators later counted 30 bullet holes in one of the buses.
As bullets flew and windows shattered, one of the students, Aldo Gutiérrez, was shot in the head. The first call to an emergency dispatch number was received at 9:48 p.m. Police officers shot at students who tried to rush to Mr. Gutiérrez’s aid.
Another student was shot in a hand; the bullet sheared off several fingers. He sought shelter behind a truck, where two police officers ran over to him, and kicked and punched him. A third student was struck in an arm by a bullet. Ambulance crews managed to retrieve the three wounded students and take them to a hospital, along with a fourth student who suffered an asthma attack.
“They all felt confusion, terror and helplessness,” wrote the panel, five lawyers and human rights experts from around Latin America.
At one point, the police made a group of students who were hiding in the third bus disembark and lie on the ground. About 10:50 p.m., they were taken away in six or seven patrol cars. They are among the 43 students who disappeared.
Meanwhile, the two buses that took the southerly route had also run into trouble. About 9:40 p.m., just as the three-bus convoy was intercepted near the northern beltway, the police cut off one of the southbound buses, shattered its windows with tree branches and shot tear gas inside to flush out the passengers.
The passengers were pulled from the bus and taken away: the rest of the 43 missing students.
Elsewhere in the city, the police had stopped the other southbound bus. The students on board, who had received word by telephone of the other attacks, got off the bus and fled into woods.
In a measure of the violent pandemonium that overcame Iguala that night, another bus and several other civilian vehicles came under attack even though they had nothing to do with the students.
Los Avispones, a soccer team of high schoolers from the city of Chilpancingo, had played a match that night against a local team in Iguala. By 11:15 p.m., the players were aboard their bus and heading home. Their route out of Iguala took them through a state police roadblock where they were rerouted because of the confrontation between the students and the police, witnesses said.
About seven miles outside Iguala, gunmen fired on the bus, killing a soccer player and the driver, and wounding seven other passengers. The attackers also fired at other passing cars, killing a 40-year-old woman who was riding in a taxi
Witnesses said the gunmen had included police officers, and ballistic tests found that some of the weapons used in the attack belonged to the Iguala municipal police department.
“The most probable hypothesis is that the bus had been confused for one of those carrying the student teachers,” the investigators wrote.
Some soccer players, including one who had been wounded in the eye and was bleeding profusely, managed to drive to a nearby army battalion but were offered no help. “They indicated that they couldn’t do anything because it wasn’t in their jurisdiction,” a witness testified.
Elsewhere, on routes leading from Iguala to Ayotzinapa, at least two roadblocks were set up by unidentified gunmen, and one by police officers from the city of Huitzuco. Two civilians were wounded by gunfire at one of the roadblocks.
The expert panel concluded that “the joint action shows a coordinated modus operandi to stop the flight of the buses.”
Meanwhile, at the entrance to the northern beltway, students who had survived the police fusillade against the three-bus convoy began to emerge from their hiding places and regroup at the scene around 11 p.m. The police had left by then, and the students sought to record the evidence of the attack while trying to communicate with their classmates in the other buses.
Journalists, as well as some teachers, began to show up, and by midnight an impromptu news conference was taking shape in the middle of the road.
About 12:30 a.m., a white sport utility vehicle and a black car drove by, their occupants taking photos of the gathering. Some were wearing bulletproof vests and hoods. Some witnesses said they also had seen a police car in the area.
Fifteen minutes later, the vehicles returned, and three men jumped out and fired on the news conference from close range. Two young men were killed, and other people, including students and teachers, were wounded.
The survivors fled into the surrounding blocks. A teacher and several students ran to a clinic to find help for the wounded. No doctor was present, but despite their appeals to emergency dispatchers and to military personnel who appeared at the clinic, an ambulance did not arrive for more than an hour.
As late as 3 a.m., the bodies of the two young men still lay in the street, uncovered, in the pouring rain.
By dawn, the situation had calmed down, and the surviving students who had been hiding across the city received word by telephone that it was safe to come out. Over the course of the morning, they gathered at the local offices of the attorney general, where they met with the authorities.
That morning, the authorities also found the body of another student, Julio César Mondragón, who had been at the news conference. He had fled when the shooting began and had become separated from the group.
His facial skin and muscles had been torn away from his head, his skull was fractured in several places, and his internal organs were ruptured. His condition, the investigators wrote, “shows the level of atrocities committed that night.”