A couple who have been on the run for two years have been arrested on suspicion of torturing a seven-year-old to death and sexually abusing and trafficking their other children. 

Edgar Salvador Casian-Garcia, 34, and his girlfriend, Araceli Medina, 38 were in the top 15 of the US Marshals’ Service Most Wanted list.

The pair were arrested in Mexico and have been charged with murder and multiple child sex abuse offences.

Five of their children were rescued. Investigators said they believed the couple were abusing and trafficking their children.

Two of Casian-Garcia’s daughters, aged 8 and 3, were found abandoned in Tijuana, Mexico, in 2020.

They allegedly showed signs of “severe physical and sexual abuse,” the Marshals Service said in February.

The body of the girls’ brother was found dumped in Washington state in February 2022. Investigators believe he was tortured to death.

The couple crossed the border into Mexico in June 2021, which investigators thought was an attempt to flee after the boy’s death.

The Marshals Service said they might have had five children with them, three of Medina’s children from a previous marriage and two children Casian-Garcia shared with another woman.

John Bischoff, of the National Centre for Missing and Exploited Children, said on Friday he was grateful the children had been rescued.

“The crimes that Araceli Medina and Edgar Casian-Garcia are charged with are heinous,” he said.

The couple are in custody in Mexico and are expected to be extradited to the US to face criminal proceedings, the centre said.

They are charged with first-degree aggravated murder, four counts of rape of first-degree child and three counts of first-degree assault of a child.