A couple, detained in Mexico while transporting human body parts in a baby carriage, has admitted to killing 20 people, twice the number originally suspected.

Under interrogation, the man, identified as “Juan Carlos N”, confessed on Monday to raping and murdering 20 women, and selling their body parts and belongings, Alejandro Gomez, the chief investigator on the case, said.

Carlos and his wife, “Patricia N” – their last names withheld in accordance with Mexican laws – were arrested on Thursday in Ecatepec, a violence-hit suburb northeast of Mexico City, on suspicion of killing 10 women.

In custody, the man gave detailed accounts of those murders, and then revealed to investigators that he and his wife had killed 10 other people, as well, according to Gomez.

Prosecutors are now trying to establish whether their claim is true, or the boast of a “psychopath” and “serial killer”, he said.

“He described it in a completely natural way … I would say he actually seemed happy to have done this,” Gomez said in an interview with Mexican radio network, Formula.

“He wants people to see his picture, to know his name … I would obviously classify this person as a murderer, a serial killer,” he said.

The man also claimed he was forced to dress as a woman by his mother, which he said sparked off his hatred against women.

Single mothers

A psychiatric examination was conducted on the couple before they were presented before a local court on Sunday.

The test said Carlos has “a mental disturbance consistent with psychosis and a personality disorder” while his wife has been “mentally disabled since birth, and also has acquired induced delirium”.

“But both can distinguish between right and wrong,” Gomez said, adding that the couple was living with their three children, including a baby.

When authorities searched the two houses belonging to the couple, they found human remains in cement-filled buckets and wrapped in plastic bags inside a refrigerator, as well as clothes apparently belonging to some of their victims.

The man told investigators that he and his wife lured their victims, many of whom were young mothers, with offers of discount on dresses for their babies.

“They were single mothers … and they needed someone who could help them find inexpensive baby clothes,” said Gomez.

Investigators tracked down the couple by tracing the calls the missing women had made to them, he said.

Outrage in Ecatepec

The case has triggered shock in Mexico, even by the standards of a country plagued by violent crimes.

Hundreds of people protested in Ecatepec, carrying candles and white flowers, to demand action by the authorities to deal with an explosion of violence against women and girls.