The students went missing near Iguala, Guerrero on Sept. 26 after clashing with police and masked men, sending shockwaves across Mexico and prompting thousands to march in the beach resort of Acapulco on Friday to demand answers about their fate.
Authorities have arrested dozens of police, who are believed to have links to a gang called Guerreros Unidos, or "United Warriors," which split from the infamous Beltran Levya Cartel.
On Friday, officials said they had captured the group's leader, Sidronio Casarrubias Salgado, along with a collaborator, weapons and vehicles. They said he was currently giving a statement to authorities.
Attorney General Jesus Murillo Karam told a televised press conference the arrest marked "the beginning of a new route of investigation that can lead us more quickly and easily to the truth."