This post was originally  published on Sin Embargo and is reproduced here under our partnership agreement.
One year ago, 43 students disappeared after being detained and kidnapped by police in the city of Iguala, in the south of Mexico. Authorities concluded  that they were kidnapped by a group of criminals who killed them and incinerated their bodies to be left by a nearby trash collection site. Doubts still exist about this conclusion.
1. Who were the students?
They were young adults from poor families who studied at the rural Ayotzinapa school, an institution known for its strong political activism, to be teachers. The majority were in their first year of study and had spent just a few months at the school, located 125 kilometers south of Iguala, in the Guerrero state of Mexico.
2. What happened in Iguala?
The normalistas  (teaching students) from Ayotzinapa were accustomed to seizing buses on roads to use for demonstrations. Last September, they intercepted one close to Iguala, and the driver reached an agreement with the group to drive toward the bus terminal to let the passengers off, according to information from experts from the Inter-American Commission on Human Rights.
3. Were the 43 students on the bus?
No, fewer than 10 of them went. In the terminal, the driver left the students locked in the bus. Those trapped students called their friends for help. More normalistas arrived in two buses and together they seized three more vehicles and pelted another one with stones.
4. Is that why the police followed them?
For years, the police had permitted the hijacking of buses to avoid violence. On September 26 in Iguala, a three-hour ferocious chase took place: municipal police shot at them, killed six people, wounded 40 others, and turned over 43 people to the Guerreros Unidos cartel.
5. Were the six people killed all students?
Only three of them were students. A bus carrying a youth football team called “Los Avispones” was also attacked. The driver, a 15-year-old football player, and a taxi passenger died in the attack.
6. Why was there so much violence?
Some of those detained later mentioned they thought that in the mix of students were members of the criminal rival group Los Rojos who had infiltrated the group. Inter-American Commission on Human Rights experts believe that something else could have been a possible cause for the altercation: drugs or drug money could have been in one of the buses, without the young people knowing, since drugs are often trafficked from Iguala to Chicago.
7. Why are there doubts about the explanation of the bodies at a garbage dump, if two of the students have been identified?
Although some of those detained talk about how the young people were incinerated, and the district attorney's office says that the remains were in a bag in the river next to the garbage dump, Argentinian specialists summoned by family members do not agree with this version of events since they weren't present when the bag was discovered. Meanwhile, the Inter-American Commission on Human Rights experts have ruled out that there was a huge fire at the site.
8. Will they be able to identify the remains one day?
With difficulty. Experts have recovered 60,000 charred fragments, and 17 of them with the greatest chances of containing DNA have been mailed to a lab in Innsbruck. Up until now, only one student, Alexander Mora, could be identified with certainty and another one, Jhosivani Guerrero, with moderate certainty.
9. What consequences did this case have for Mexico's government?
Ayotzinapa represented a big loss for President Enrique Peña Nieto. Iguala was governed by an opposing party, so the government has been criticized for delaying action on the investigation and for declaring that the “all victims incinerated” version was the “true story” of the case.