Tamaulipas state attorney general's office spokesman Ruben Dario Rios Lopez told the McAllen newspaper The Monitor that the search for David Michael Hartley was suspended Thursday so that authorities can look into new strategies to find him.
He says authorities hope to be able to resume the search for Hartley "in a few days."
Hartley's wife, Tiffany, says they were on their way back to the U.S. from photographing a historic Mexican church when pirates in boats opened fire on them, shooting her husband. She says she tried to help her husband but had to flee because they kept shooting.
Earlier Thursday a U.S. consulate official said Hartley may have been a victim of mistaken identity.
"I think what you had is two innocent American tourists who mistakenly stumbled into a bad area and were pursued and the shooting occurred," said Brian Quigley, spokesman for the U.S. consulate in Matamoros, across the Rio Grande from Brownsville, Texas.
Quigley was responding to a report by Stratfor, an Austin, Texas-based public policy research group that analyzes the Mexican drug war. The report suggests that David and Tiffany Hartley may have been mistaken for drug runners and attacked.
Tiffany Hartley, of McAllen, Texas, says that on Sept. 30, she and her husband, David, were returning to the United States from Mexico where they went to photograph a historic, half-submerged church.
They were crossing Falcon Lake on Jet Skis when pirates who patrol the Mexican half of the lake opened fire, shooting David in the back of the head. Tiffany Hartley says she barely escaped with her life after vain attempts to save her husband while men on three speedboats pursued them, firing their guns.
Texas officials have warned boaters to stay away from the Mexican side of the lake after several fishermen were robbed earlier this year. Hartley's death was the first violent attack on the lake, which was created by damming a section of the Rio Grande.
The Stratfor report says the Hartleys' truck holding the Jet Skis had Tamaulipas, Mexico, license plates, which may have led pirates or drug gangsters to think they were from a rival gang and were spying on them.
The Hartleys lived in Reynosa, Mexico, a city across the border from McAllen, until recently, when David Hartley's employer, an oil and gas company, decided it was too dangerous for them to live in Mexico.
Tamaulipas state is the center of a violent rivalry between the Gulf Cartel and Los Zetas, a brutal drug gang made up of former Mexican special-forces soldiers. The search for Hartley's body has been repeatedly hampered by threats of an ambush from drug gangs, presumably the Zetas.
This week, a state police commander in Tamaulipas, Rolando Flores, who was investigating the Hartley disappearance, was killed, his decapitated head delivered in a suitcase to a local Mexican army post.
U.S. Secretary of State Hillary Rodham Clinton condemned the investigator's killing Thursday, calling it an example of "the absolute barbarity" displayed by terrorists and criminals around the world.
Clinton, traveling in Europe, told ABC's "Good Morning America" that the U.S. government is doing everything possible to help the Hartley family.
"The beheaded body of the brave Mexican investigator that just showed up shows what we're dealing with," Clinton said.
Mexican authorities say they don't know if Flores' death was related to the Hartley case because he was working on numerous investigations involving drug gangs. The killings of police officials have become common in Mexico.
Quigley said there is "a possibility" that there is a connection.
Although no sign of Hartley or his Jet Ski have been found after more than a week of searching the lake, Quigley and local officials in Texas say they still believe Tiffany Hartley's story. The Stratfor report theorized that once the killers realized Hartley was an American, they destroyed the body to avoid a U.S. backlash.
"We have absolutely no reason whatsoever to doubt anything Mrs. Hartley has told us," Quigley said.
The search, he said, will continue.
"The Mexican government is to be applauded. They continue with this search even with the unfortunate killing of the investigator," he said.