His wife Tiffany who was with her husband but couldn't save him expressed frustration in an "Early Show" interview on Tuesday that the Mexican government wasn't doing enough to help.
She said, "As far as we know, we don't think they have been looking. And there is -- we understand the possibility that the people who did this probably have him. And that's why maybe they can't find him."
But on Monday, a Mexican official seemed to question whether the attack took place at all.
In a statement, Marco Antonio Guerrero Carrizales, district attorney for the Miguel Aleman Province, writes, "We are not sure. We are not certain that the incident happened the way they are telling us."
CBS News correspondent Don Teague reports that family members have countered by criticizing what they see as a lackluster search effort by Mexican authorities.
And now they may have some support as Zapata County Sheriff Sigifredo Gonzalez says he has a witness who saw Tiffany Hartley being chased by men in a small boat.
Father Dennis Hartley told the Associated Press, "I don't think at this time…Mexico is really doing anything."
That should change, according to Gonzalez, who met with Mexican authorities last night. He told CBS News they promised to search all day or until they find David Hartley.