Grisly slaying won't stop investigation

(CNN) – The decapitation of a Mexican investigator has had a chilling effect on the search for the killers of an American man, but South Texas investigators are vowing to solve the mystery.

David Hartley was shot to death two weeks ago on the Mexican side of Falcon Lake. Investigators now say the likelihood of finding his body is slim, and the severed head was meant to send a message to stop the search.

Hartley's wife, Tiffany, said Wednesday that she met with the deceased investigator just last week. The meeting took place at a border checkpoint in McAllen, TX and lasted about an hour.

"I met him. He sat right next to me," Tiffany Hartley said. "We talked through a translator and he just seemed like a really good guy who really wanted to just do good for his country."

Tiffany Hartley said she was concerned that other investigators might quit the case, fearing for their own lives. The man who was killed, Rolando Flores, was the lead investigator.

"It makes me worry that nobody's going to want to take over," she said. "But right now they're still searching."

Tiffany has reported that Mexican officials have asked her to return to Mexico to fill out additional paperwork, although she said she spent almost four hours doing just that, talking with investigators, and answering questions early on in the investigation.

She says she will not go over the border again, saying she just doesn't feel safe.

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