FREEHOLD A stain on the inside of a pair of jeans found in Paul Caneiro’s basement after his brother’s family was killed in 2018 initially did not provide useful information to investigators when examined using traditional DNA analysis, he testified Monday a state DNA expert.

But when the DNA extracted from the stain was re-examined last year and run through a cutting-edge software program that the New Jersey State Police first began using in 2022, it was revealed that a part of it is the DNA of Caneiro’s killer. grandson, Jesse Caneiro, 11, testified state police DNA expert Christine Schlenker.

Schlenker took the witness stand at an ongoing preliminary hearing on the admissibility of DNA evidence at Paul Caneiro’s upcoming trial. Caneiro, 57, of Ocean Township, is accused of killing his brother Keith, 50, sister-in-law Jennifer, 45, niece Sophia, 8, and nephew Jesse, whose bodies were found during a fire at Keith’s. Caneiro’s Colts Neck mansion on November 21, 2018.

For the DNA evidence to be admissible, Superior Court Judge Marc C. Lemieux, the Monmouth County circuit judge, must find that the new computer program known as STRmix produces reliable results and that the method it uses to generate them calculus is generally accepted in the scientific field. community.

STRmix uses a method known as probabilistic genotyping, which was designed to analyze small amounts and complex mixtures of DNA that often cannot be analyzed by traditional methods.

Probabilistic genotyping departs from the traditional DNA analysis method of random match probability, which generates a statistic on the probability that a match to a DNA profile will be found in the general population.

Probabilistic genotyping instead analyzes admixtures to which multiple individuals have contributed to generate a “likelihood ratio” that an individual of interest can be either included or excluded as a contributor to the admixture.

Schlenker testified that the DNA from the stain on the inside of the jeans found in Paul Caneiro’s basement was a mixture of DNA from two people. The STRmix program found that it was 2.73 septillion times more likely that Jesse Caneiro contributed DNA to that two-person mix, she said.

STRmix also concluded that it was 53 billion times more likely that Paul Caneiro did not contribute to the mix, Schlenker said.

Jeans and other items were seized from Paul Caneiro’s home after authorities say he set the home on fire to throw off investigators and make it look like the entire Caneiro family was targeted by violent criminals. .

Authorities say Paul Caneiro first set a slow fire in his brother’s home in an attempt to cover up the crimes of Keith, who was shot four times in the head and once in the back, as well as Jennifer and their two children, who have been repeatedly. stabbed and badly burned. Jennifer Caneiro was also shot in the head.

The profile of the mixture of DNA inside the jeans was also compared to the DNA of Jennifer, Keith and Sophia Caneiro and Sean Edson, a firefighter who cut himself fighting the fire at Paul Caneiro’s house. Jennifer and Keith Caneiro and Edson were ruled out as possible donors of the sample, while the comparison with Sophia’s DNA was “uninformative,” Schlenker said.

Schlenker said he used STRmix to analyze DNA from the inside collar of a long-sleeved shirt found in the defendant’s home and concluded that the DNA was that of a mixture of two people and that Paul Caneiro was likely 110 million times higher than not to contribute. most of that mixture.

When the two items were analyzed in 2018, before the state police lab began using STRmix, it was determined that the DNA was “not of good quality and quantity for comparison, so no comparisons could be made.” Schlenker said.

Schlenker said he analyzed a third item in the Caneiro case, a tag on a pair of jeans from the defendant’s home, but did not detect DNA on it, so no further analysis was conducted.

Last week, the judge heard testimony from a DNA analyst at Bode Technology, a private forensics lab in Lorton, Va., to whom the Monmouth County District Attorney’s Office sent items from the Caneiro case to be tested before state police began using STRmix. The analyst, Danielle Reed, testified that DNA from another area on the jeans was a mixture of DNA from three people. STRmix analysis of the admixture revealed that there is very strong support that Paul and Sophia Caneiro contributed to the admixture, Reed testified.

Before Schlenker took the stand Monday, Jennifer Thayer, director of the state police DNA lab, testified about the process undertaken to validate the reliability of the STRmix software before the state police began using it.

The process involved creating mixtures of DNA from known people and running it through the program to check that the results were correct.

“STRmix is ​​able to do more with these mixes than we could previously, and everything came together as expected,” Thayer testified.

But under questioning by Christopher Godin of the state Public Defender’s Office, Thayer acknowledged that the lab’s validation studies included “very minimal” consideration of how the software handled DNA from relatives and contained only samples from a pair of descendants in studies.

“We’ve since decided to do some relative studies, but they’re ongoing,” Thayer testified.

In the STRmix challenge, the Public Defender pointed out limitations in the software’s ability to analyze mixtures of related people because relatives share what are known as alleles, which are sequences of DNA that a person inherits from each parent.

The outcome of the hearing will have statewide implications for STRmix because the state police now use it and because it has never been challenged or found reliable in a New Jersey court.

Kathleen Hopkins, a reporter in New Jersey since 1985, has covered crimes, court cases, legal issues and nearly every major crime trial that has hit Monmouth and Ocean counties. Contact her at [email protected].

This article originally appeared on the Asbury Park Press: New technology found murdered nephew’s DNA on Caneiro’s pants: expert