FREEHOLD As Paul Caneiro awaits trial for the 2018 murders of four of his family members, the fate of the sophisticated computer software used to analyze the DNA evidence against him now lies before Monmouth County Superior Court.
Years of preparation began Tuesday for Supreme Court Justice Marc C. Lemieux to scrutinize the reliability of software that deviates from traditional methods of DNA analysis.
The final obstacle to Caneiro’s trial in the murder of his brother, sister-in-law, niece and nephew. The hearing will determine the admissibility of DNA evidence derived from computer software known as STRmix, which uses a method known as probabilistic genotyping to create DNA profiles.
The outcome of the hearing will have statewide implications beyond the Caneiro case, as the New Jersey State Police recently began using STRmix in its DNA lab.
At the start of the hearing, Lemieux provided an overview of the STRmix software, which was developed by the New Zealand Institute of Environmental Science and Research and Forensic Science of South Australia.
“This software uses probabilistic genotyping analysis to interpret mixed DNA profiles commonly found at crime scenes,” Lemieux said.
“Using statistical methods, the STRmix software generates millions of hypothetical DNA profiles, evaluates the strength of these profiles against evidence and determines the most likely combination of profiles that can explain the DNA profile,” said Lemieux.
“While other jurisdictions in the United States have admitted evidence tested with STRmix software, no court in the State of New Jersey has done so,” Lemieux said.
Caneiro’s attorneys at the District Attorney’s Office filed a motion to exclude the STRmix evidence in 2022, but it took years before their experts were allowed to examine the program’s proprietary source codes under a negotiated protective order.
Caneiro, 57, of Ocean Township, is expected to stand trial early next year for the murders of his brother, Keith, 50, sister-in-law, Jennifer, 45, niece, Sophia, 8, and nephew, Jesse, 11. in the Colts Neck mansion by Keith Caneiro.
Emergency responders responding to a slow-burning fire at the home on Nov. 21, 2018, discovered the bodies.
Keith Caneiro, found on the front lawn, had been shot four times in the head and once in the back. Jennifer Caneiro and the two children, who were found in the house, were stabbed repeatedly and badly burned. Jennifer Caneiro was also shot in the head.
Hours earlier, firefighters in Ocean Township responded to Paul Caniero’s home to put out a fire that authorities say he planned to throw off investigators and make it look like his entire family was being targeted by violent criminals.
Authorities allege that Paul Caneiro committed the murders after Keith, his business partner, discovered he was stealing from companies they co-owned.
The first witness at Tuesday’s hearing on the DNA evidence was Monica Ghannam, a forensic scientist at the Union County Prosecutor’s Office Forensic Laboratory in Westfield.
Ghannam said the lab began using the STRmix program exclusively for its DNA analysis in 2017.
Previously, the lab used a traditional DNA analysis method known as random match probability, which was limited to analyzing mixtures of DNA from one or two sources and occasionally a mixture from three people, Ghannam said.
“We can now assess mixtures for four people, while before we could hardly assess mixtures for three people,” said Ghannam.
Assistant Monmouth County Prosecutor Nicole Wallace asked Ghannam to assess STRmix’s reliability.
Ghannam replied: “very high.”
Ghannam explained that the random match probability method generates a statistic about the probability that a match to a DNA profile can be found in the general population, while a ratio used by STRmix compares the DNA profile to the probability that it is a person of interest can include or exclude. from the sample.
Another advantage of the STRmix technology is that it can remove the profile of a known contributor to a DNA mixture, so that what remains of the mixture can be better analyzed, Ghannam explains.
The STRmix technology was validated through a process that compared the results to those derived from the manual analysis of DNA profiles of known contributors, Ghannam explained.
Under cross-examination by Christopher Godin of the prosecution, Ghannam admitted that she is not a software developer, was not involved in the development of STRmix and has never seen the program’s source code.
The hearing is expected to last several weeks.
A reporter in New Jersey since 1985, Kathleen Hopkins covers crime, trials, legal issues and virtually every major murder case affecting Monmouth and Ocean counties. Contact her at khopkins@app.com.
This article originally appeared on Asbury Park Press: Hearing on DNA in Colts Neck murders underway as Caneiro trial looms
