A Mexican couple caught carrying dismembered human remains in a baby carriage may have killed as many as 20 women, a top prosecutor says.
The man confessed to 20 killings, but gave details including the names of only 10 victims, said Alejandro Gomez, the chief prosecutor of Mexico State, which is located north and west of Mexico City.
The couple was detained last week in Ecatepec, on the northern outskirts of the capital.
Mr Gomez told Radio Formula the man appeared proud of the killings. He also said there were signs the man suffered a personality disorder and resented his mother and a previous girlfriend.
"What seemed macabre to me is that this person mentioned 10 cases in which he gives details, the names of the victims; he gave us the clothing they had on at the time," Mr Gomez said.
His companion apparently helped him lure the women.
Most were single mothers, and the couple apparently lured their victims with offers of cheap baby clothing.
The couple, who were identified only by their first names Juan Carlos and Patricia in a police statement, also reportedly confessed that they had sold one of the dead women's two-month-old baby to another couple.
The baby was recovered and the other couple was detained.
Police placed the couple under surveillance after phone records showed they had contacts with three missing women.
On Thursday (local time), police caught them coming out of a house with a baby carriage carrying plastic bags with dismembered human body parts which the pair allegedly intended to dispose of in a nearby vacant lot.
Police said they went to the lot and found more body parts, but they were in such bad condition that forensic tests will be needed to identify them.
Police said the couple acknowledged disposing of other bodies in a similar fashion. Mr Gomez said on Monday investigators have found more dismembered remains in two houses.
Mr Gomez said the man confessed to sexually abusing some of the victims before killing them.
Prosecutors said the couple sold the body parts but it was not clear to whom.
Mexico State has suffered from waves of women's killings in recent years.