![Soldiers stand guard outside the prosecutor's office and the facilities of the Forensic Medical Services, in Matamoros, Tamaulipas,, on March 7.](https://imagenes.elpais.com/resizer/v2/5Q2TL3WI6VTUVWNWEZQXTDMZG4.jpg?auth=f21c37901125e507a6df216b4c3aa748016b1c4a984a06f4dc8c3c1b296d3b7c&width=414&height=311&smart=true)
Unanswered questions surround kidnapping of US citizens in Mexico
The motive for the attack on a group of four friends in Matamoros remains shrouded in mystery, as does the identity of the perpetrators and how investigators located them
The motive for the attack on a group of four friends in Matamoros remains shrouded in mystery, as does the identity of the perpetrators and how investigators located them
More than 112,000 Mexicans remain missing nationwide, in many cases years or decades after they disappeared
Mexican authorities are working on the assumption that the kidnap of four US citizens in Matamoros, two of whom were found dead, was a case of mistaken identity by drug cartels
The other two US citizens missing since Friday have been found alive. Mexico’s Secretary of Security, Rosa Icela Rodríguez, confirmed that one person has been arrested
In photos and videos posted on social media, a group of armed men can be seen taking the hostages after a shootout, among them a woman, the only one who seems conscious
Authorities have issued yellow and orange warnings with subzero temperatures, heavy rain, sleet and frost forecast in nothern and central areas
The Border Project, led by the Argentine Forensic Anthropology Team, has managed to identify the bodies of more than 280 people who died during the perilous crossing