Rhonita LeBaron Miller's car after the group was attacked. Photo / Supplied
Mexican authorities have arrested a municipal police chief for his suspected links to the killing of three women and six children of US-Mexican origin in northern Mexico last month, local media and an official have said.
Suspected drug cartel hitmen shot dead the nine women and children from families of Mormon origin in Sonora state on November 4, sparking outrage in Mexico and the United States.
Several Mexican media outlets reported that law enforcement agents arrested Fidel Alejandro Villegas, police chief of the municipality of Janos, which lies in the neighbouring state of Chihuahua, on suspicion of involvement in the crime.
The reports said he is suspected of having ties to organised crime, but details of his alleged role are not clear.
A federal official, speaking on condition of anonymity, confirmed the arrest of Villegas, which follows the detention of other suspects earlier in the investigation.
Mexican officials believe the women and children were killed after becoming caught up in a dispute between local drug cartels battling for control of the area.
Under pressure from the Trump administration, Mexican President Andres Manuel Lopez Obrador sought US co-operation in the case, inviting the FBI to help in the investigation.
THREE FAMILIES MASSACRED IN NORTH MEXICO
Mexican police and heartbroken relatives said three mums, all with dual US-Mexican citizenship and living in a Mormon community just south of the border, had been travelling in the north of Mexico in a convoy when they were targeted last month.
Police said the mums — Christina Langford Johnson, Dawna Ray Langford and Rhonita LeBaron Miller — had been driving the three SUVs on a remote and unpaved mountain road at around 1pm local time that Monday when they were attacked.
The cars, filled with their children, had been travelling from the Mormon community of La Mora in the Mexican state of Sonora down to Pancho Villa in Chihuahua.
The three mums and six of their children — including infant twins — were murdered in the ambush.
But eight young children survived by hiding. Five of the surviving children were badly wounded, including one child shot in the face.
The three families had left the community together but a flat tyre delayed one of the families.
The car that fell behind was the first to be found by police shot up and burnt out with the bodies of one woman — identified as Rhonita (LeBaron) Miller — with her twin babies and two other small children dead inside.
A relative of Miller, who did not want his name used for fear of retaliation, said in an interview that when they finally made it to the scene where the ambush started they found a burnt-out Chevy Tahoe.
Inside, they saw the charred remains of Miller, 30, her 10-year-old daughter, a son, 12, and her eight-month-old twins. They were "burnt to a crisp", the relative said.
The gunmen had riddled the vehicle with dozens of bullets and apparently hit the gas tank, causing it to explode.
"When we were there, the cartels from Sonora, there were probably 50 or 60 of them, armed to the teeth, about a mile on this side," said the relative.