Expert explains how new DNA technology could help solve JonBenét Ramsey's murder case

Techniques that can pull usable genetic information from small or degraded samples could give investigators new options in the JonBenét Ramsey murder case, a forensic expert has said.

Cassie Leigh, a certified forensic technician and crime analyst, told UNILAD the technology could finally shed light on a case that has baffled investigators since 1996.

"DNA is incredibly complex, which is both a blessing and a curse for investigators," Leigh said. "When a sufficient, high-quality sample is available, the odds of two unrelated people sharing the same DNA profile are practically impossible."

"With newer DNA technology, investigators may now be able to develop useful genetic profiles from samples that previously would have been difficult to analyze," she explained.

She said SNP testing and investigative genetic genealogy can ‘look for familial connections, rather than relying solely on traditional law enforcement DNA databases.’ "In a case like JonBenét's, that could potentially open up entirely new investigative leads, provided the available evidence is suitable for this type of testing."

There have been three main theories into her death (Helen H. Richardson/ The Denver Post)

How do SNP testing and genetic genealogy work on old DNA evidence?

"Traditionally forensic DNA (the king most people associate with crime shows) typically examines specific regions of DNA called STRs (short tandem repeats)," Leigh said.

"SNP testing works a bit differently; instead of looking at repeating patterns, scientists examine individual DNA letters (A, T, C, and G) at hundreds of thousands of specific locations throughout the DNA. Think of it as looking at tiny spelling differences in an incredibly long instruction manual."

She said it can sometimes produce 'useful genetic information from smaller or more degraded samples,' though she cautioned: "It isn't a magic fix for every sample, esppecially when DNA from multiple people is mixed together."

Genetic genealogy takes another route. "Forensic genetic genealogy works by using DNA recovered from a crime scene to search for potential genetic relatives of an unidentified individual," she said. "The Golden State Killer case is probably the most famous example of forensic genetic genealogy helping solve a decades-old criminal investigation."

What challenges could investigators face using these DNA techniques?

Leigh did not hold back when it came to the original investigation.

"everyone who followed this case from the beginning knows what an absolute trainwreck the original crime scene investigation was. The scene wasn't properly secured, and multiple people had access to the home both before and after the crime occurred," she said.

JonBenét Ramsey was just six years old when she was brutally murdered on Boxing Day 1996 (YouTube/CNN)

"Unsecured scenes create significant challenges when interpreting trace evidence (like DNA) becaue of the high probability of contamination, secondary transfer, and DNA left behind by people who had legitimate reasons to be in the home."

Resources are often another obstacle. "Many people don't know that most crime labs are backed up and only accept a certain amount of evidence per case, which can significantly delay investigations," she added.

"Some of these samples are incredibly small, and certain testing methods can consume some or even all of the available DNA," Leigh said, warning that investigators 'may only have one opportunity to get a usable result.'

Even a match is not the end of the road. "Familial DNA matches don't automatically identify someone as a suspect, much less prove they committed a crime," she said, adding that detectives must still establish where potential suspects lived and whether they had access to the scene.