not really as potentially, there still could be some family matches in Gedmatch. People can die. When they die, they can not be prosecuted, so legally, they are not criminals. But if they left their DNA at the crime scene, they can be found.
52-year-old Seattle murder case is the oldest ever to be solved using genealogy – The Seattle Times
However, interesting thing...
“Moore said when she ran the suspect’s DNA, she came up with two distant cousins — people who shared less than about 2% of the killer’s DNA — and a handful of people who were even more scarcely related. She saw surname patterns suggesting Polish ancestry, and the suspect’s DNA profile was predicted to be about 16% Native American.
She worked her way backward using those clues, and eventually found a couple — a man born in 1828 in Kentucky and a woman born Missouri in 1837 — from whom both of the distant cousins were descended. She then followed the generations forward from that ancestral couple, and found Frank Wypych, who was born in Seattle and would have been 26 at the time of the killing.“
These distant cousins shared about 2% of DNA with the guy. With the exception of my own family, people whom I know, no one in Gedmatch shares as much as 2% with me. So if they were trying to find a common ancestor, say, with me, they would have to go way higher that 1800 es.
Just as an example why a match can not always work.
Either the BG has very distant relatives in Gedmatch. Or, they had closer ones, but persuaded them to pull out their DNAs out of Gedmatch. (Which would be suspicious).
Another version - the LE were “sitting” on this DNA, waiting, and started working with genetic genealogists by the time when Gedmatch requested additional step - opting in to permit owner’s DNA to be viewed by the police. And now... there might be a match to BG’s DNA, but the match has not made his DNA open for criminal work (sometimes people lose interest in genealogy, and stop checking Gedmatch at all).
If this is the case, then it is a big mistake.
Let us imagine the situation. LE, after 2 years, decided to work with the Parabon. It probably takes the Parabon some time to put the DNA into the right format. Supposedly, they had the time to do it. Even ran the test and found a match.
They may already have a tree. They might very well guess who the perp is. But they can not use this information in court, because while they were building the tree, Gedmatch changed the rules re opt-ins, that matching relative chose not to opt in, and became invisible. Nothing can be used in court now.