Story highlights The Guerrero state legislature must now find a replacement

Forty-three students intending to protest in Iguala vanished September 26

Police say ex-mayor and his wife are responsible for the disappearance

Activist priest says the students were shot, bodies burned

The legislature of Mexico's Guerrero state must now find a replacement after the governor effectively stepped down, yielding to a growing political crisis over a mass kidnapping.

After weeks of calls for his resignation, Gov. Angel Aguirre on Thursday asked for a leave of absence to put the focus back on solving the case of the missing students.

By law, governors in Mexico cannot resign, so asking for a leave of absence can be a euphemism for stepping down in a crisis situation. The state legislature must name a new governor to finish Aguirre's term, which ends next year.

His critics said Aguirre didn't act quickly enough in the days after 43 students went missing last month or take measures to minimize the impact of the crisis.

The governor did not agree with that assessment.

"From the very first hours" of the disappearance, the governor said, "the state government took immediate measures to detain police officers who were directly involved and other individuals who were identified as participants in these criminal acts with the purpose of locating the missing students and pay the necessary attention to the victims."

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Photos: Photos: Missing Mexican students Photos: Photos: Missing Mexican students Missing Mexican students – Forty-three students remain missing after armed men ambushed buses carrying students in southern Mexico on on September 26 .The Mexican state of Guerrero posted images and offered a reward of 1 million pesos ($74,000) for information leading to the missing students. Images of three missing students were not available. Hide Caption 1 of 41 Photos: Photos: Missing Mexican students Hide Caption 2 of 41 Photos: Photos: Missing Mexican students Hide Caption 3 of 41 Photos: Photos: Missing Mexican students Hide Caption 4 of 41 Photos: Photos: Missing Mexican students Hide Caption 5 of 41 Photos: Photos: Missing Mexican students Hide Caption 6 of 41 Photos: Photos: Missing Mexican students Hide Caption 7 of 41 Photos: Photos: Missing Mexican students Hide Caption 8 of 41 Photos: Photos: Missing Mexican students Hide Caption 9 of 41 Photos: Photos: Missing Mexican students Hide Caption 10 of 41 Photos: Photos: Missing Mexican students Hide Caption 11 of 41 Photos: Photos: Missing Mexican students Hide Caption 12 of 41 Photos: Photos: Missing Mexican students Hide Caption 13 of 41 Photos: Photos: Missing Mexican students Hide Caption 14 of 41 Photos: Photos: Missing Mexican students Hide Caption 15 of 41 Photos: Photos: Missing Mexican students Hide Caption 16 of 41 Photos: Photos: Missing Mexican students Hide Caption 17 of 41 Photos: Photos: Missing Mexican students Hide Caption 18 of 41 Photos: Photos: Missing Mexican students Hide Caption 19 of 41 Photos: Photos: Missing Mexican students Hide Caption 20 of 41 Photos: Photos: Missing Mexican students Hide Caption 21 of 41 Photos: Photos: Missing Mexican students Hide Caption 22 of 41 Photos: Photos: Missing Mexican students Hide Caption 23 of 41 Photos: Photos: Missing Mexican students Hide Caption 24 of 41 Photos: Photos: Missing Mexican students Hide Caption 25 of 41 Photos: Photos: Missing Mexican students Hide Caption 26 of 41 Photos: Photos: Missing Mexican students Hide Caption 27 of 41 Photos: Photos: Missing Mexican students Hide Caption 28 of 41 Photos: Photos: Missing Mexican students Hide Caption 29 of 41 Photos: Photos: Missing Mexican students Hide Caption 30 of 41 Photos: Photos: Missing Mexican students Hide Caption 31 of 41 Photos: Photos: Missing Mexican students Hide Caption 32 of 41 Photos: Photos: Missing Mexican students Hide Caption 33 of 41 Photos: Photos: Missing Mexican students Hide Caption 34 of 41 Photos: Photos: Missing Mexican students Hide Caption 35 of 41 Photos: Photos: Missing Mexican students Hide Caption 36 of 41 Photos: Photos: Missing Mexican students Hide Caption 37 of 41 Photos: Photos: Missing Mexican students Hide Caption 38 of 41 Photos: Photos: Missing Mexican students Hide Caption 39 of 41 Photos: Photos: Missing Mexican students Hide Caption 40 of 41 Photos: Photos: Missing Mexican students Hide Caption 41 of 41

Mexico's attorney general this week issued arrest warrants for the former mayor of Iguala, the city where the students were kidnapped; that official's wife; and the city's former public safety director. Attorney General Jesus Murillo Karam called the three the "probable masterminds" of the September 26 events in Iguala.

That day, students from a teachers college in nearby Ayotzinapa were on their way to stage a protest in Iguala. When former Mayor Jose Luis Abarca and his wife learned the protest would disrupt an event led by the latter, they gave orders to Public Safety Director Felipe Flores Velasquez to send police forces to prevent the students from protesting.

"The order to confront those people came from the police department's command center, straight from A-5, code name used to identify the Iguala mayor," Murillo said. The attorney general said his office learned the information from interrogations of police officers and gang members detained in the last month and allegedly involved in the incident.

Police blocked the highway leading into the city and shot at the students as they arrived in buses and a van. One student was killed.

Footage from the scene showed a white van left in the middle of the road with its windows blown out and the doors wide open.

Officers took the students away, Murillo said, then handed them to a local criminal gang known as Guerreros Unidos (United Warriors), which not only had infiltrated the police department but was also complicit with Abarca, his wife and the public safety director. All three disappeared the day after the clashes between police and the students.

Members of the Mexican federal police and army have taken over the Iguala Police Department and assumed all security responsibilities.

The students remain missing, and 53 people, including 36 officers and 17 suspected gang members, have been detained.

A Roman Catholic priest and well-known activist who works with migrants and trafficking victims revealed details this week about the kidnappings, saying the students were forced to walk to a remote location and then shot.

"Some who were wounded but still alive, with others who were already dead ... were put on top of firewood and set on fire with diesel," the Rev. Alejandro Solalinde said. He said he has given his information to prosecutors.

The case has become a political crisis, with opposition lawmakers asking President Enrique Peña Nieto to dissolve the entire Guerrero state government and take charge. Peña Nieto has said his government will not spare any efforts until the students are found and justice is done.

"Violence, whatever its origin, goes against what we are as a country. Violence will never be a solution or pave the way toward a better future," the President said.

Mexican authorities are offering a reward of nearly $5 million for information leading to the students and solving the case.