Mexican authorities have arrested the former head of Mexico’s federal anti-kidnapping special unit in connection with the forced disappearance of 43 students from Ayotzinapa in 2014. Gualberto Ramírez Gutiérrez was taken into custody early Sunday morning. He was first arrested in 2015, accused of ordering the killing of the 43 students, but he was ultimately released three years later. Arrest warrants were also issued against eight other soldiers over their possible involvement in the mass kidnapping. Click here to see our extensive coverage of Ayotzinapa.