Authorities are searching for a pair of Mexican brothers they suspect in the reported border-lake shooting of a missing American, a police official in the border state of Tamaulipas said Sunday.
David Hartley has not been seen since his wife reported the Sept. 30 attack on Falcon Lake on the Rio Grande.
Mexican investigators believe brothers Juan Pedro and Jose Manuel Zaldivar Farias may have killed Hartley as he took photos of a sunken church from a personal watercraft, Tamaulipas State Police unit chief Juan Carlos Ballesteros said.
The pair already are wanted for allegedly belonging to a gang of pirates that operates on Falcon Lake, which straddles the U.S.-Mexico border, and for terrorizing a Mexican town at the south end of the lake.
Ballesteros gave no other details of the investigation.
The announcement came a day after the Mexican government announced that it had opened a federal investigation into the reported shooting on the lake and strongly denied delaying action on looking for the missing man or his attackers.
Falcon Lake is a dammed section of the Rio Grande, 25 miles long and 3 miles across. Pirates have robbed boaters and fisherman on the Mexican side, prompting warnings by Texas state officials, but Hartley's death would mark the first violent fatality on the lake.
Mexico's foreign ministry said the federal attorney general's office had begun an investigation based on Tiffany Hartley's testimony about the attack to Mexican consulate officials in McAllen, Texas, where she lives.
Mexican authorities continued to search Falcon Lake and its Mexican shore for Hartley, with support from the Mexican military and U.S. agencies. Tiffany Hartley says her husband was shot in the head while they used personal watercrafts on the lake.
She told Sheriff Sigifredo Gonzalez of Zapata County, Texas, that she tried to retrieve her husband but left him behind and fled when the attackers started shooting at her.
The Tamaulipas state civil protection agency said it has 102 people searching the lake and shore with the help of three boats, five all-terrain vehicles and 53 trucks.