Jet Ski Victim's Parents' Pain, Grief, Anguish

David Hartley's wife, Tiffany Hartley, is preparing to return to their home state of Colorado as the probe of David's death continues, reports CBS News Correspondent Don Teague.

The Hartleys were jet skiing on the Mexican side of Falcon Lake Sept. 30, on the U.S.-Mexican border when, she says, David was shot in the head and killed.

Then, the Mexican investigator leading the case was beheaded.

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Pictures: David and Tiffany Hartley

Now, the search for Hartley's body has been called off because, says the U.S. State Department, of "the tragic death of investigator Rolando Flores and dangerous conditions on the ground."

Authorities on both sides of the border think a brutal Mexican drug cartel was behind both deaths, Teague says, adding some officials believe this may be been a case of mistaken identity, with enforcers for one cartel thinking the Hartleys were rival drug-smugglers.

Mexican authorities say the FBI has joined the investigation, and David's mother, Pam Hartley, confirms to "Early Show Saturday Edition" co-anchor Chris Wragge that she and her husband, Dennis Hartley, were contacted by the bureau.

Dennis told Wragge it's "not really" surprising the search for his son's body was ended. He says authorities there aren't "really that well-equipped to carry out a good search and be safe during a search. It would take a fairly good force of people to secure the area, so it does not surprise me. It is a dangerous area for them to conduct a search."

Dennis says he welcomes the FBI's involvement since, "Anything will help at this point" to "keep the communication lines going with the Mexican government."

When he heard about Flores had been killed, Dennis says, he "was just shocked and saddened that another son or father or husband has been lost, and it's just very tragic event that took place there."

"David wouldn't want anybody putting their life, you know, in danger to hunt for him. I know he wouldn't," Pam assured Wragge.

She says Tiffany and David were getting set to move back to Colorado, after living in southern Texas for almost three years. Her voice shaking, Pam lamented that, "They were almost home and this happens. … They were just out to take pictures of (a) church, I mean, David loves history, and that was something he wanted to do before they came home. They've wanted to do this for a long time. And just to know that they were down there taking pictures and that, it just -- it doesn't seem real."

Both Pam and Dennis expressed some dissatisfaction with the job Washington did early on letting them know about developments. "The information was just slow in coming and very delayed," he said. "Sometimes, we would hear things going on and then a few hours later hear that it wasn't, and it just seemed like it was just -- just really not hearing a lot of, you know, good information or as to, at that time, what involvement there was of any U.S. agencies at that time.