Credibility of Bloodstain Pattern Analysis, Like Many Forensics, Under Fire

Forensic science has played an increasingly larger role in criminal courtrooms across the country – particularly in cases involving more serious crimes, such as homicides, robberies and sexual assaults. However, the scientific veracity of this evidence has come under fire in recent years as even more advanced science has proven some of those convicted largely on these older forensics were indeed innocent as they’d always claimed.criminal defense attorney

In 2015, The Washington Post reported the U.S. Department of Justice and the FBI both formally acknowledged that almost every examiner in the FBI forensics unit gave flawed testimony in nearly every trial in which they offered evidence against criminal defendants in the nearly two decades preceding 2000. Of the methods to which they testified were forensic hair analysis and forensic bite mark analysis. Among those cases effected, 32 were sentenced to die, with 14 having already been executed or died in prison. This was acknowledged by the agency after a study found that in 95 percent of nearly 300 cases reviewed, forensic examiners overstate those forensic matches in ways that favored the prosecution’s case.

Other forensic disciplines touted as practically airtight in criminal trials for decades had by that time been largely discredited, including shoe and tire impressions and handwriting. A 2009 report from the National Academy of Science released a groundbreaking report revealing these “sciences” were not as credible as what they claimed to be, as they aren’t rigorous, grounded in peer-reviewed research and outcomes often rely on judgments of individual practitioners. The report stated opinions offered by these “experts” were generally more subjective than scientific. Specific to bloodstain patterns, the report stated complex patterns fluids make as they exit wounds are “highly variable,” making valid interpretations difficult or impossible.

Recently, a ProPublica investigation delved into another reportedly dubious forensic analysis method, bloodstain pattern analysis. The case they highlighted was that of a once-loved high school principal in Texas who was sentenced to 99 years in prison for the murder of his wife, an elementary school teacher, who was shot in their home in 1985 – a key piece of evidence in his conviction being bloodstain pattern analysis. 

A local news reporter first got involved in 1991, when the family of another local murder victim – a 16-year-old girl whose murder was never solved – agreed one the anniversary of her death to discuss their frustration with the local police department’s failure to identify a suspect. They encouraged him to also to look into the death of the principal’s wife, which occurred just four month’s after the teen’s.

In the course of his investigation, the journalist was given access to the evidence files from the local police chief, and noted there were a number of leads the department had never followed up on. One of those involved two men seen around midnight (16 hours after the murder) at a local car dealership that had just had their van painted from off-white to green. Both had lengthy rap sheets and stated the vehicle, which had no license plate, was being readied for an upcoming hunting trip.

The reporter interviewed the convicted husband, who insisted on his innocence and lamented law enforcement’s failure to follow up on key clues, such as a cigarette butt found on the kitchen floor neither the crime scene, when neither he nor his wife smoked. There were also unidentified fingerprints nearby as well.

At each of the man’s two trials, prosecutors alleged that between 9:15 p.m. one evening and the following morning when the schoolteacher was found, the defendant drove 120 miles from his hotel room in heavy rain despite poor eyesight to the couple’s home, shot his wife and returned to hotel room before morning. There were no eyewitnesses and the couple had no history of conflict. A flashlight speckled with blood was found in the defendant’s car four days later, but he denied having put it there. It wasn’t clear what connection that might have had. The blood type was O, which was the decedent’s blood type, but it’s also the blood type of half the human population. At the trial, “expert” testimony was given that the blood on the lens of the flashlight was “back spatter,” which indicated a close-range shooting, and opined the flashlight was likely in the killer’s hand at the time of the murder. No blood was found anywhere else inside the car, which the expert said could be explained by the killer changing his or her clothes and shoes before fleeing. At the time of the trials, the law enforcement officer who testified as an expert had taken a one-week course in bloodstain pattern analysis. The class was taken the same year as the murder, but these classes are still offered at police departments to this day.

The ProPublica reporter took the same course, and he too was given a “certificate of training” after a single exam. The instructor of the course expressly told the class, “You won’t be walking out of her an expert.” Yet courts across the country have allowed police to testify after having undergone this same 40-hour course, and the instructor also advised the class on what to say if they were called to testify at a criminal trial, using words like, “probably” and, “the best explanation is.”

Bloodstain pattern analysis gained popularity after the high-profile trial of Ohio Dr. Sam Sheppard of his pregnant wife. A bloodstain pattern analyst testified in a retrial for the defense, resulting in a subsequent acquittal. By the early 1970s, bloodstain pattern analysis courses were being offered at police departments all over the country. They typically cost anywhere from $200 to $700. Many have testified in criminal trials – including the O.J. Simpson trial in 1995.

The credentials of these witnesses have been challenged over the years, but numerous judges relied legal precedent – specifically on the previous use of the discipline in older cases –  when deciding when to allow it.

The reality is the pattern of bloodstains may only reveal a limited amount of information. For instance, it might give us an idea of where a suspected intruder was injured before fleeing. But going much further beyond that really involves a great deal of guesswork.

The ProPublica piece details a great volume of additional evidence seeming to strongly support the theory that the two homicides were linked. The man suspected in that case was a former police officer with a history of violence and harassment against women who later committed suicide, after which several associates of his later came forth to reveal his confessions to them.

This case – and numerous others that resulted in formal exoneration – are illustrative of why you need an experienced, dedicated and dogged Fort Lauderdale criminal defense attorney, willing to meticulously comb through evidence and vigorously challenge the prosecution’s case.

Call Fort Lauderdale Criminal Defense Attorney Richard Ansara at (954) 761-4011. Serving Broward, Miami-Dade and Palm Beach counties.

Additional Resources:

Blood Will Tell, May 31, 2018, By Pamela Colloff, ProPublica

More Blog Entries:

U.S. Supreme Court: No Warrant? No Driveway Search., June 17, 2018, Fort Lauderdale Criminal Defense Attorney Blog