Mexican officials say three Texas siblings, found dead in northeastern Mexico this week, had been tied-up and shot in the head.
Tamaulipas attorney general Ismael Quintanilla, says their suspected abduction earlier this month might have been orchestrated by local security officials.
(SOUNDBITE) (Spanish) ISMAEL QUINTANILLA, ATTORNEY GENERAL OF THE BORDER STATE OF TAMAULIPAS, SAYING:
"We are giving instructions to the agents from the public prosecutor's office so that investigations continue and people who need to be called upon for a statement are called and go on until we are able to find those responsible and remand them."
The investigation comes amid a search for another 43 missing students -- thought to have been abducted with the help of police.
