Option 1 would include any scenario in which he is guilty and some in which he is not guilty. Somehow, if he did this, BK managed not to get any other shred of his DNA in 1122 King Rd, so the DNA on the snap would logically have gotten there at some time prior to the time of the murders.
Option 2 - is actually very likely and here is a real life example of Option 2 actually happening - so not only is this scenario possible, it has actually happened before AND people have been wrongly convicted. Here is but one example:
We leave traces of our genetic material everywhere, even on things we’ve never touched. That got Lukis Anderson charged with a brutal crime he didn’t commit.
www.pbs.org
"We leave traces of our genetic material everywhere, even on things we’ve never touched. That got Lukis Anderson charged with a brutal crime he didn’t commit."
"Back in the 1980s, when DNA forensic analysis was still in its infancy, crime labs needed a speck of bodily fluid — usually blood, semen or spit — to generate a genetic profile.
That changed in 1997, when Australian forensic scientist Roland van Oorschot stunned the criminal justice world with a nine-paragraph
paper titled “DNA Fingerprints from Fingerprints.” It revealed that DNA could be detected not just from bodily fluids but from traces left by a touch. Investigators across the globe began scouring crime scenes for anything — a doorknob, a countertop, a knife handle — that a perpetrator may have tainted with incriminating “touch” DNA.
But van Oorschot’s paper also contained a vital observation: Some people’s DNA appeared on things that they had never touched."
We leave traces of our genetic material everywhere, even on things we’ve never touched. That got Lukis Anderson charged with a brutal crime he didn’t commit.
www.themarshallproject.org
Option 3 - where this could come into play is the fact the Idaho crime lab found no DNA on the sheath at all. The DNA on the sheath was not discovered until the sheath was sent to a lab in Texas. So that brings into question the entire chain of custody as well as if it was partial or a complete DNA sequence. Could the lab in Texas have taken a partial DNA sequence, and recombined it to create a genealogical DNA profile that pointed to the wrong family? Well, it seems with partial DNA that is very possible.
How Forensic DNA Evidence Can Lead to Wrongful Convictions - JSTOR Daily
"The ABA urged lawyers not to oversell DNA evidence and suggested that courts take the standards of the lab into account when considering DNA evidence. “Telling a jury it is implausible that anyone besides the suspect would have the same DNA test results is seldom, if ever, justified,” the report states."
"Partial profiles will match up with many more people than a full profile. And even full profiles may match with a person other than the culprit. Further complicating matters, a single DNA profile might be mistakenly generated when samples from multiple people are accidentally combined. It’s a messy world."
"At times, DNA evidence has been misused or misunderstood, leading to miscarriages of justice. A man with Parkinson’s disease who was unable to walk more than a few feet without assistance was convicted of a burglary based on a partial DNA profile match. His lawyer insisted on more DNA tests, which exonerated him. In 2011,
Adam Scott’s DNA matched with a sperm sample taken from a rape victim in Manchester—a city Scott, who lived more than 200 miles away, had never visited. Non-DNA evidence subsequently cleared Scott. The mixup was due to a careless mistake in the lab, in which a plate used to analyze Scott’s DNA from a minor incident was accidentally reused in the rape case.
Then there’s the uncomfortable and inconvenient truth that any of us could have DNA present at a crime scene—even if we were never there. Moreover, DNA recovered at a crime scene could have been deposited there at a time other than when the crime took place. Someone could have visited beforehand or stumbled upon the scene afterward. Alternatively, their DNA could have arrived via a process called secondary transfer, where their DNA was transferred to someone else, who carried it to the scene."
This case is such an incredibly heinous crime it is imperative, IMO, that we know for certain that the perpetrator has been caught. Otherwise that criminal or those criminals will be free do this again and that is terrifying.
