Investigation into triple slayings in Jupiter remains active

JUPITER (CBS12) — More than 40 hours after bullets rang out along Mohawk Street, a Jupiter Police mobile command unit remains parked outside of the home where three people died.

We watched Tuesday afternoon as crime scene techs and investigators walked on and off of the property, still roped off with crime scene tape. It’s a property on a quiet street that’s still an active crime scene.

Palm Beach Atlantic University Forensics Professor Tiffany Roy knows how to process a crime scene. She spent five years with the Massachusetts State Police working with their DNA crime lab unit.

http://cbs12.com/news/local/investigation-into-triple-slayings-in-jupiter-remains-active

Gill: How misuse of DNA evidence has led to miscarriages of justice

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DNA analysis has revolutionised forensic science; helping to catch prolific murderers and shining a light on miscarriages of justice that have seen innocent people wrongfully convicted of serious crimes. Such is the power of DNA to identify, convict, and exonerate, that many perceive it to be infallible. Yet DNA evidence has a number of limitations and the costs of not being aware of these can be huge.

As a forensic geneticist of 35 years standing, I have been very closely involved with every stage of the development of DNA profiling since its discovery in 1985. Yet over recent years, I have become particularly concerned with standards of practice and the court statements written by some forensic scientists.

Read more here

What are jurors thinking when they hear expert evidence

Based on these tests, Schweitzer et al found that jurors’ opinions of the forensic evidence presented is most heavily swayed by the expert’s experience level. Other factors, such as whether the evidence was obtained by high or low tech means, or whether or not the methods used had been scientifically validated only minimally impacted the views of the jury. It’s important to note, however, that while the expert’s experience level effected opinions on the evidence presented, it did not impact the final verdict.

Read more here

After Lab Closure, Daunting Questions on DNA-based Convictions Remain

The shuttering of the Austin Police Department’s forensics lab after an audit found unscientific protocols and contamination of evidence has delayed pending cases and led to a debate about how the lab should be operated.

Now, the Travis County district attorney’s office is faced with another chunk of the problem: Figuring out how many cases were resolved using possibly bad DNA evidence.

Thousands of people — defense attorneys estimate 4,000 to 5,000, while prosecutors say fewer than 3,600 — were convicted using evidence processed by the Police Department’s forensics lab between 2004 and 2016, when lab procedures might have been compromised. The Capital Area Private Defender Service, which represents area defense attorneys, said in a report this month that anywhere from 1 percent to 40 percent could see their convictions overturned.

That wide range makes it clear how little anyone knows about the actual scope of the forensics flaws. It spells a daunting task for local officials as they come up with a plan to fund a review of those cases and potential retesting of evidence.

Read more.

Source: American-Statesman

How DNA Evidence Went From Airtight to Error-Prone

Blind faith in any technology can be dangerous -- especially when it comes to areas of forensic science such as DNA fingerprinting. For example, if police have “DNA evidence” against a suspect, most juries will assume that’s proof of guilt. But while the technology for analyzing DNA has become vastly more sensitive since it was first introduced in courts in the 1990s, crime labs are working with ever more minute traces -- sometimes just a few molecules -- and drawing inconsistent or erroneous conclusions from them. In fact, there’s good reason to believe DNA evidence has sent people to prison for crimes they didn’t commit. Read more here.

DA to reopen 2000 closed cases in Broward County with DNA errors

Two years ago, Boynton Beach forensic expert Tiffany Roy was hired to double-check DNA evidence swabbed from a knife handle. What she found was troubling: The Broward Sheriff’s Office crime lab had mistakenly claimed it was conclusive.

It wasn’t.

As New Times previously reported, Roy complained to the American Society of Crime Lab Directors, which investigated and agreed with her findings.

Now, the crime lab faces revocation of its accreditation, and the Broward State Attorney’s Office will likely have to reopen thousands of closed cases.

Read more at Broward New Times

PCAST Report Final Issued

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Report on Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature-Comparison Methods

On September 20, 2016, PCAST released a Report to the President on Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature-Comparison

https://www.whitehouse.gov/administration/eop/ostp/pcast/docsreports

No More 'Reasonable Degree of Scientific Certainty'

Forensic science, already under review and scrutiny from an alphabet-soup of federal agencies, is getting another reining-in from the Department of Justice.

Terms such as “reasonable scientific certainty” can no longer be used, DOJ labs have to post internal validation studies online, and forensic scientists will be expected to uphold a 16-part “Code of Professional Responsibility for the Practice of Forensic Science,” announced Loretta Lynch, the U.S. Attorney General, in a memorandum last week.

Read more on forensic magazine.com here

Subjective DNA Mixture Analysis, Used in Thousands of Cases, Blasted by WH Panel

DNA mixtures can by mind-bogglingly complex. The genetic traces of more than two people can create statistical chaos indicating someone’s DNA is included, or excluded, from a sample – based simply on the judgment of the person doing the testing.

This chaos has been interpreted by mathematical forensic analysis. But it involves subjective estimations by trained experts.

Read more at forensic magazine.

Evaluation of forensic DNA mixture evidence: protocol for evaluation, interpretation, and statistical calculations using the combined probability of inclusion

Background: The evaluation and interpretation of forensic DNA mixture evidence faces greater interpretational challenges due to increasingly complex mixture evidence. Such challenges include: casework involving low quantity or degraded evidence leading to allele and locus dropout; allele sharing of contributors leading to allele stacking; and differentiation of PCR stutter artifacts from true alleles. There is variation in statistical approaches used to evaluate the strength of the evidence when inclusion of a specific known individual(s) is determined, and the approaches used must be supportable. There are concerns that methods utilized for interpretation of complex forensic DNA mixtures may not be implemented properly in some casework. Similar questions are being raised in a number of U.S. jurisdictions, leading to some confusion about mixture interpretation for current and previous casework.

Results: Key elements necessary for the interpretation and statistical evaluation of forensic DNA mixtures are described. Given the most common method for statistical evaluation of DNA mixtures in many parts of the world, including the USA, is the Combined Probability of Inclusion/Exclusion (CPI/CPE). Exposition and elucidation of this method and a protocol for use is the focus of this article. Formulae and other supporting materials are provided.

Conclusions: Guidance and details of a DNA mixture interpretation protocol is provided for application of the CPI/ CPE method in the analysis of more complex forensic DNA mixtures. This description, in turn, should help reduce the variability of interpretation with application of this methodology and thereby improve the quality of DNA mixture interpretation throughout the forensic community.

Read the full article here

Allegations Against BSO Crime Lab DNA Unit Sustained on Appeal

A panel of experts from the council that accredits forensic laboratories has sustained allegations that the Broward County Sheriff's DNA lab has been using improper methods to analyze certain DNA evidence.

The lab has been using inappropriate practices to calculate the likelihood that one person - usually a criminal suspect - left his DNA on evidence that has DNA from more than one person, the accrediting council board found.



Source: Allegations Against Broward DNA Lab Sustained on Appeal | NBC 6 South Florida http://www.nbcmiami.com/news/local/Broward-DNA-lab-problems-sustained-on-appeal-385753611.html#ixzz4Dh1SZID3 
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Broward County Crime Lab DNA Mixture Problems

In March 2015, prosecutors temporarily stopped sending evidence to what was then a state-of-the-art city forensics lab in Washington, DC, over concerns technicians had bungled cases and misstated the likelihood DNA had been left at a crime scene. Earlier this month, the crime lab for the entire city of Austin, Texas, was shut down amid concern its technicians weren't following proper procedure. Both events amounted to earthquakes in the criminal-justice world: Crime labs are responsible for handling nearly every piece of physical evidence. They need to be accurate.

Now, according to an independent forensics analyst, the very same DNA issues have struck the scandal-plagued Broward Sheriff's Office Crime Lab. The place is just now recovering from allegations a former drug analyst potentially tainted thousands of separate cases.

read more here

Austin Crime Lab DNA Unit Mixture Interpretation Trouble

The Austin Police Department is closing for most of the rest of the year, as it revamps its system of DNA analysis, according to officials.

The shutdown will last four to six months, and will involve new training, certification, re-certification, auditing, and the hiring of a new lab director, Chief Art Acevedo announced at a Friday press conference.

“We decided to initiate a cease of operations,” the chief told reporters. “The Texas Forensic Science Commission identified some concerns for us.”

The Austin laboratory has been used extensively to analyze trace DNA, even in property-crime cases, Acevedo said.

While it is temporarily closed, the existing prosecutions will be “triaged.” The criminal cases which are time sensitive and can’t be handled by the Texas Department of Public Safety labs will be contracted out to private labs, Acevedo said.

read more at Forensic Magazine.

DNA Evidence Is Not Infallible

Earlier this month, the Texas Forensic Science Commission raised concerns about the accuracy of the statistical interpretation of DNA evidence, and it is now checking whether convictions going back more than a decade are safe.

Despite how it is often portrayed, in the media and in courts, the forensic science of DNA is far from infallible. Particularly concerning is that police and prosecutors now frequently talk of 'touch DNA' — genetic profiles of suspects and offenders that have been generated in a laboratory from just a handful of skin cells left behind in a fingerprint.

Research done by me and others at the University of Indianapolis in Indiana has highlighted how unreliable this kind of evidence can be. We have found that it is relatively straightforward for an innocent person's DNA to be inadvertently transferred to surfaces that he or she has never come into contact with. This could place people at crime scenes that they had never visited or link them to weapons they had never handled.

Such transfer could also dilute the statistics generated from DNA evidence, and thereby render strong genetic evidence almost insignificant. (The statistics issue is reportedly the focus of the Texas investigation.)

read more at: http://www.nature.com/news/forensic-dna-evidence-is-not-infallible-1.18654?