4 minute read
Scientist defends DNA software in Caneiro murder trial
John Buckleton, a prominent scientist with the Institute of Environmental Science and Research in New Zealand, countered skepticism surrounding STRmix software, stating that it has never produced a false inclusion in cases.
FREEHOLD – The co-creator of the contentious STRmix software, which analyzed DNA evidence linking Paul Caneiro to the brutal murder of four family members, staunchly defended the program during a two-day court hearing, addressing a barrage of inquiries regarding potential limitations and errors.
Buckleton, who serves as the principal scientist at the institute, took the witness stand on Nov. 14 and 15, affirming the reliability of STRmix as the court deliberates the admissibility of the DNA evidence it generated in advance of Caneiro’s impending trial.
Caneiro, aged 57 and hailing from Ocean Township, faces serious charges for the murders of his brother Keith, 50; sister-in-law Jennifer, 45; and his young niece Sophia, aged 8, along with his nephew Jesse, aged 11. The bodies of the victims were discovered on the scene of a horrific crime at Keith Caneiro’s Colts Neck mansion on Nov. 21, 2018.
After the murders, DNA identified as a mixture of Paul and Sophia Caneiro was uncovered on gloves and jeans found in the basement of Paul Caneiro’s Ocean Township residence.
During questioning on the second day of the hearing, Monmouth County prosecutor’s deputy Christopher Decker asked Buckleton, “Are you satisfied in the fact that STRmix is generally accepted in the scientific community?” Buckleton confidently answered, “Yes.”
When pressed further by Decker on whether there was any doubt regarding STRmix’s suitability for application in cases, Buckleton reiterated with an emphatic, “No.”
The outcomes stemming from this hearing hold significant ramifications statewide for the use of STRmix, as the software recently gained traction within New Jersey State Police laboratories. However, it faces its first major legal scrutiny in New Jersey courts.
Unlike conventional DNA analysis, which typically relies on random match probability to calculate the chances of finding a match within the general population, STRmix employs a cutting-edge approach known as probabilistic genotyping. This approach is tailored for processing small DNA quantities and complex mixtures that traditional testing methods often fail to analyze effectively.
On the second day of testimony, Decker challenged Buckleton regarding allegations of “miscodes” present within STRmix, which have surfaced in defense critiques. Buckleton acknowledged that there were indeed 15 coding errors, all of which have since been rectified and publicly addressed on STRmix’s official website. He asserted that these errors had minimal effects on criminal case outcomes.
Decker highlighted a finding from one defense expert, which claimed that these errors influenced 60 criminal proceedings, necessitating recalibrations of the “likelihood ratio” in about 24 of those cases. Buckleton replied, “It caused a relatively minor difference in the population reference counting,” countering the notion that the errors caused significant harm.
Buckleton dismissed claims from the defense expert suggesting that the software’s errors impacted thousands of criminal convictions. “It did not affect thousands of convictions,” Buckleton stated unequivocally, clarifying that in the 60 cases examined, adjustments were made, but many yielded identical results post-correction. He insisted that all identified issues were resolved before any trials commenced.
Christopher Godin from the Public Defender’s Office pressed Buckleton about the implications of these errors, observing that many criminal cases—particularly those resulting in guilty pleas—might not reveal potential miscodes affecting DNA evidence. “In those cases, it’s not necessarily likely a person would discover that a miscode affected DNA evidence in that case,” Godin argued.
In response, Buckleton retained his stance, stating, “Miscodes have not affected DNA evidence. The miscodes that we have detected to date all have a minor effect on the numerical values or on a peripheral functionality.”
Godin further queried Buckleton on the software’s limitations regarding familial DNA analysis, pointing out that relatives share alleles, which can complicate the interpretation of DNA evidence. Buckleton conceded, “Yes,” confirming that family members can sometimes deposit DNA that might falsely suggest belonging to another relative.
Godin posited a serious concern that the DNA analysis conducted in the Caneiro case may have incorrectly excluded Keith Caneiro from the relevant DNA profiles, adversely impacting Paul Caneiro’s defense. “There are exclusions that STRmix has made that are very harmful to Mr. (Paul) Caneiro,” Godin noted, to which Buckleton affirmatively replied, “Absolutely.”
Authorities assert that Paul Caneiro allegedly committed these gruesome murders after his brother Keith uncovered his embezzlement from their shared business ventures. The bodies of the victims were tragically discovered by first responders at the scene of a fire that was igniting at the Colts Neck mansion. Reports indicate that Keith Caneiro had been shot four times in the head and once in the back, while Jennifer and the two children suffered multiple stab wounds and were severely burned, with Jennifer also shot in the head.
It is alleged that following the murders, Paul Caneiro set fire to the family mansion in an attempt to conceal the crime and then ignited his own residence to mislead investigators into believing a dangerous criminal was targeting the entire family.
Caneiro is slated to face trial in this highly publicized case in the early part of next year.
The hearing on the DNA evidence is anticipated to resume on Monday, Nov. 18.
What are the key advantages of using STRmix software over traditional DNA analysis methods in complex forensic cases?
**Interview with John Buckleton on STRmix Software and the Caneiro Murder Trial**
**Interviewer:** Thank you for joining us today, Dr. Buckleton. As the co-creator of STRmix software, you recently testified in the Caneiro murder trial. Can you explain how STRmix differs from traditional DNA analysis methods?
**John Buckleton:** Thank you for having me. STRmix utilizes probabilistic genotyping, which allows it to analyze complex mixtures of DNA—something traditional methods often struggle with. Instead of looking at one DNA profile, STRmix evaluates multiple contributors to create a more accurate interpretation of the evidence.
**Interviewer:** There have been concerns raised in court about the reliability of STRmix. You stated it has never produced a false inclusion in cases. Can you elaborate on that?
**John Buckleton:** Absolutely. STRmix has undergone extensive testing and validation. To date, it has maintained its integrity and accuracy in various case scenarios. The software is generally accepted within the scientific community, and I stand by its reliability.
**Interviewer:** During your testimony, you addressed claims of “miscodes” in STRmix. What can you tell us about those?
**John Buckleton:** Yes, there were 15 coding errors identified, but they have been fixed and publicly acknowledged on our website. Importantly, these miscodes had minimal effects on case outcomes. It’s crucial to understand that while adjustments were made in some cases, many results remained consistent post-correction.
**Interviewer:** A defense expert suggested these errors could have affected numerous criminal convictions. How do you respond to such claims?
**John Buckleton:** I can confidently say that those claims are exaggerated. The miscodes did not affect thousands of convictions as suggested. Our assessments indicated that while some recalibrations were necessary, they did not significantly change the outcomes of the majority of cases.
**Interviewer:** The implication of these errors raises questions about cases that resulted in guilty pleas. Can STRmix’s limitations impact the justice system in these scenarios?
**John Buckleton:** While any software has limitations, I want to emphasize that our detected miscodes have had only minor effects. The integrity of DNA evidence remains intact, and we continuously strive to ensure transparency and accuracy in our processes.
**Interviewer:** Thank you, Dr. Buckleton, for your insights on this crucial topic. It’s clear that the discussions around STRmix are pivotal for its future use in the justice system.
**John Buckleton:** Thank you for having me. It’s crucial to maintain an open dialogue about scientific methods in court to uphold the integrity of justice.