Illegal injections: How Texas is breaking the law, one execution at a time

Hours later, when the victim’s body was found, police marked tire tracks circling the body — none of which matched Leal’s car. Witnesses later testified they saw some of the men from the party with the victim’s purse, scattering and possibly even trying to destroy its contents. Leal’s sister, at a post-conviction hearing, claimed to have seen at least two men at the party with blood on their legs, though the state claimed she wasn’t a credible witness.

Remarkably, no other suspects were questioned or charged with rape. Even more alarming: sperm swabs were taken from the victim’s body but never tested for DNA. Leal has always claimed those tests would prove he never raped the victim. “That’s the part of this case I have found so outrageous,” Babcock said. “I do not understand why none of those men were ever questioned, charged, or prosecuted for rape. I can’t believe that. I mean, when I look at the investigation, this is the kind of investigation that you would be shocked to find even in a robbery case. ... There are so many gaps, and frankly, I think the way that investigation was handled, it’s insulting to the victim.”

At trial, the prosecution also presented so-called Luminol tests, saying they proved the victim bled inside Leal’s car when he attacked her. While the Luminol reacted to something, the trial record shows the substance was never actually tested. Luminol, which forensic scientists deem a precursory test for blood, reacts to a number of substances, including animal blood, simple household cleaners, and even some vegetable and organic compounds.

Many courts now rule out Luminol tests unless labs confirm for blood, Babcock said, arguing the evidence can be highly misleading. Babcock’s team also discovered a sworn affidavit from Leal’s father, where he claims he often used the car when he went deer hunting — something the prosecution never presented before the court, either to question the evidence or to even have it tested for Sauceda’s DNA.

Another damning piece of evidence came from a forensic odontologist who testified that bite marks found on the victim’s body matched Leal’s teeth. (Investigators never took saliva swabs to test for DNA.) The prosecution used the bite marks as evidence to convict Leal, and even used it during the punishment phase of the trial when pushing for the death penalty, saying, “Humberto, he is the wolf with his fangs bared with the blood dripping, tasting. Imagine it. Tasting her terminal fear. What does it take for an animal like that to bite her as she dies?”

Yet, the forensic science community has largely rejected so-called bite-mark technology as junk science. According to a 2009 congressionally mandated study by the National Research Council of the National Academy of Sciences, there’s “no evidence of an existing scientific basis for identifying an individual to the exclusion of others.” The technique, the study also found, proved to have an alarmingly high rate of false-positive matches, and shouldn’t be considered valid forensic evidence.

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