Oct. 18, 2010 -- The wife of a man allegedly killed by pirates on a lake that straddles the U.S.-Mexico border will return to FBI offices today to resume a marathon session of questions from Mexican authorities.
Tiffany Hartley, wife of David Hartley, who went missing after the Jet Ski incident Sept. 30 on Falcon Lake, endured eight hours of questioning by Mexican investigators Friday. She has said she refused a request to come to Mexico for further questioning, out of fear of a possible arrest.
"I just don't think that's a wise decision," Hartley told "Good Morning America." "I think they do believe my story, but I don't know what their plan is -- why they need me to go over there when I've signed every document they told me."
When asked if she thought she would be arrested if she went to Mexico, Hartley said, "Possibly."
Hartley said that she hopes that by speaking with the investigators, without an attorney, she can convince them to continue their search for her missing husband. The search was called off last week after a lead investigator for the Mexican authorities was beheaded, allegedly by members of a drug cartel.
David Hartley was last seen Sept. 30 when Tiffany said he was shot by Mexican pirates while the couple rode Jet Skis on the Mexican side of Falcon Lake. In a heartwrenching 911 call, a seemingly panicked Tiffany Hartley explained to the dispatcher that David was shot in the head and she was not strong enough to pull his body onto her Jet Ski. Neither David's body nor his Jet Ski have been recovered.
Tiffany Hartley spent much of the weekend packing up her South Texas home for a move to Colorado.
Search to Continue After Gruesome Beheading
Though the search has not yet started, last week Mexican authorities said they would press their search for the body of an American tourist even after the lead investigator was decapitated.
"I can't even explain how my heart is just broken for him and his family. There aren't any words," Tiffany Hartley said last week of recently deceased Rolando Flores. "He was just such a nice guy, and he really wanted to do what he could for us."
The widow said last week she gets search updates from Mexican authorities almost daily.
Zapata County, Texas Sheriff Sigifredo Gonzalez said he felt for Flores' family.
"They're going to now be without a father, without a husband when in fact all they were trying to do was search for the body of Mr. Hartley," Gonzalez said last week.
Flores' severed head was delivered Oct. 12 in a suitcase to a military post near the border with Texas. His wife had said he was working late on the Hartley case the night before and never came home.
Although many believe Flores' murder was the work of the drug cartels who control the waters where Hartley was killed, Mexican authorities have denied his death had anything to do with the murder investigation.
Zeta Cartel Suspected in Decapitation of Top Investigator
Earlier last week, Mexican authorities named two suspects in Hartley's murder, two Zeta drug cartel members known as Pedro Saldiva Farrias, 27, and his brother, Jose Manuel Saldiva Farrias, whose age was not given.
Juan Carlos Ballesteros, an investigator with the state prosecutor's office of the Mexican state of Tamaulipas, said both were said to be suspected members of the Zeta drug cartel from Nueva Ciudad Guerrero, near the abandoned town where David and Tiffany Hartley were sightseeing before they were ambushed.
The Hartley case highlights the ongoing turf war between Mexican drug cartels and the country's government, which has been waging a war against the growing drug violence. More than 29,000 people have died in drug violence since December 2006, with the Zeta cartel being blamed for the majority of the deaths.
Zeta is known for smuggling billions of dollars of cocaine and other drugs into the U.S. every year.
ABC News' Gina Sunseri and Emily Friedman contributed to this report.