The Texas Forensic Science Commission, a national leader in forensic science reform, has called the blood-spatter evidence in a 1985 Bosque County murder case "not accurate or scientifically supported" and even "entirely wrong." The findings and may lead to a new trial for 77-year old Joe B. who, after 30+ years in prison, is in declining health.
The commission is not meant to determine any defendant's guilt or innocence but to consider the reliability of the forensic science used to convict them. This is important because recent years have demonstrated that a large number of common forensic techniques are scientifically invalid.
In bloodstain interpretation, officers acting as prosecution witnesses often have no more than a week's training. That was the case in Joe B.'s case, and a prominent bloodstain pattern analyst showed not only that the prosecution witness's conclusions were invalid but also that he suffered from a serious misunderstanding of the science.
Joe B. was accused of killing his wife, and the primary evidence was a bloodstained flashlight found in Joe's car. This was before DNA evidence, so all the prosecution knew about blood itself was that it was Type O. That matched Joe's wife, but it is also the most common blood type.
The prosecution's witness said the blood stains on the flashlight were in a "back spatter" pattern, indicating that the killer was holding the flashlight during the murder. According to the commission's expert, this conclusion and the witness's interpretation of the flashlight and crime scene were "egregiously wrong."
"If any juror relied on any part of his testimony to render a verdict, [Joe B.] deserves a new trial," she concluded.
The commission also found that a state crime lab technician made numerous assertions about blood and trace evidence that she was unqualified to make and even gave an opinion about fiber evidence that she hadn't even tested.
Attorneys for Joe B. are now seeking a DNA test on the blood from the flashlight, which they believe will not match that of Joe's late wife. The prosecutor from Bosque County has been stonewalling the test. They will present their cases at a hearing beginning on Aug. 20. It will be up to the Texas Court of Criminal Appeals to determine if the DNA test or an entirely new trial is warranted.
This case was covered in a joint investigation by the New York Times and ProPublica, and you can find more detailed information there.
The case has already prompted reform, however. In February, the commission said that bloodstain-pattern analysis should not be performed by officers with minimal training. Instead, an accredited organization must perform the analysis if it is to be allowed in court.