Leaving the DNA behind doesn’t really identify him if his DNA is not in the system.
But nowadays the odds some relative of yours put theirs up on some family tree site is pretty high so they could narrow the suspect pool quite a bit going that route.
His DNA doesn’t need to be in any system. These days there are professionals that take DNA results and comb through the databases to find close relatives that are in the system. It’s how they caught the BTK Killer.
Leaving the DNA behind doesn’t really identify him if his DNA is not in the system.
But nowadays the odds some relative of yours put theirs up on some family tree site is pretty high so they could narrow the suspect pool quite a bit going that route.
His DNA doesn’t need to be in any system. These days there are professionals that take DNA results and comb through the databases to find close relatives that are in the system. It’s how they caught the BTK Killer.
I think you’re thinking of the Golden State Killer (among many others). BTK was caught through digital forensics, not forensic genealogy.
https://people.com/crime/btk-killer-daughter-dna-led-to-arrest/