Authorities in Mexico have arrested a key suspect in the killing of nine members of a Mormon community.
Three women and six children, all dual US-Mexican citizens, were driving through the Sonoran desert when they were killed in an ambush last year.
Roberto N is believed to have been the "intellectual architect" of the attack, Mexico's federal attorney-general's office said on Wednesday.
Known as The Mute and The 32, he is a suspected leader of La Línea cartel.
Two other suspects, thought to be members of the same cartel, were also arrested.
La Línea is a faction of the Juárez cartel and engages in arms and drug smuggling between northern Chihuahua state and the United States.
Many of its members are believed to be former police officers who were "bought off" by the Juárez cartel, switched sides and became "enforcers" for the cartel, protecting drug shipments and attacking rival gangs.
The US ambassador to Mexico, Christopher Landau, congratulated Mexican security forces for the arrests, writing on Twitter: "Excellent co-operation between the authorities of both countries. There will be justice!"
The victims were members of independent Mormon communities which broke away from the mainstream Mormon Church decades ago and settled in Mexico.
The three women and their 14 children were travelling on a remote road between the states of Sonora and Chihuahua when their vehicles were shot at by gunmen on 4 November 2019. Eight of the children survived the attack.
It is unclear why the families were attacked, but one theory is that they were mistaken by La Línea for members of a rival cartel.
Roberto N was captured along with two other men in Nuevo Casas Grandes, a city in Chihuahua state, Mexico's Attorney-General's office confirmed on Wednesday. Five weapons were also seized.
Mexican security officials have previously said that Roberto N was a former police officer.
Monday's arrest was carried out by federal prosecutors who had worked independently of officials at state level to avoid leaks in the case.
The three detainees have been transferred to the capital, Mexico City, to be charged.
Two other key suspects are already in custody in connection with the case, including one arrested on the anniversary of the attack. A number of suspected members of La Línea have also been arrested.