This is a tough one, obviously. It certainly seems to me that black Americans are the people most often victimized by people who commit crimes themselves, say, like Susan Smith, and then make up false alibis accusing phantom black perpetrators of the crime.
In this case, it's quite difficult-- I have only been able to study this on the basis of what I've read in the media, and I have had these reactions-- first, the woman seems credible, insofar as a "gut feeling" means anything. Also, the fact that the Mexican detective in charge of the investigation has been murdered also seems, to say the least, a major factor. I can't say I blame her for not wanting to travel to Mexico to participate further in the investigation. If Mexican authorities wish for her to answer further questions, they can certainly come to the U.S.
On the other hand, a few parts of her story seem suspect to me-- first, leaving a living witness behind, as Tiffany Hartley claims occurred, seems out of character for these Mexican cartel contract killers. The supposition, based on the story she tells, seems to be that the killers shot her husband, then came up to her, realized they'd hit the wrong person, and left, apparently not wanting to compound their personal sense of guilt by adding yet another mistaken homicide to their list of crimes and sins. This is not outside the realm of possibility but does seem outside the general character of the general tactics of these people, who, we might grimly recall, killed 18 people in a drug rehabilitation center, apparently in order to eliminate a single target.
Also, the Mr. Hartley's body has not been located even though he was wearing a life jacket. The Mexican government seems to think her story is not credible, though the FBI, until now, at least, seems to believe her. No way really to know the truth and it shows, yet again, the need for us to both have higher penalties for those who make false accusations and also for us to take seriously the issue of the Mexican drug cartels. When I have time to do so, I will make my case for why we need to legalize drugs in the United States-- I do not favor this policy out of any desire to romanticize drugs or drug use, but I consider legalization the only long term solution to the problem we face via the cartels.