Authorities are investigating whether police were involved in the killing of three U.S. citizens visiting Mexico who were found shot to death along with a Mexican friend more than two weeks after going missing. Parents of the three siblings, who were visiting their father, have said witnesses reported they were seized by men dressed in police gear calling themselves "Hercules," a tactical security unit in the violent border city of Matamoros heavily racked by cartel infighting. Nine of the unit's 40 officers are being questioned, Tamaulipas state Attorney General Ismael Quintanilla Acosta said.
The father of the three Americans, Pedro Alvarado, identified his children from photographs of the bodies showing tattoos, Quintanilla told local radio — although the identities have yet to be confirmed by DNA. Clothing found with the bodies also matched that of Erica Alvarado Rivera, 26, and brothers, Alex, 22, and Jose Angel, 21, who disappeared Oct. 13 along with Jose Guadalupe Castaneda Benitez, Erica Alvarado's 32-year-old boyfriend. "They were good kids," said an aunt, Nohemi Gonzalez. "I don't know why they did that to them."