[Verse 1]
For forty years the Golden State remained unsolved
Cold cases sitting dormant, mysteries unresolved
But science had been changing, DNA could speak
Genealogy and algorithms, finding who we seek
[Chorus]
Genetic genealogy, the family tree unfolds
Public databases tell the stories that DNA holds
Upload and compare, let the algorithms run
Cross-reference relatives till the guilty one is done
SNPs and markers, building bridges to the past
Finally justice found him, science solved it at last
[Verse 2]
They took the killer's profile from the evidence preserved
Built genetic markers that for decades had been curved
Into family databases, twenty million strong they searched
Finding distant cousins where his family tree had perched
[Chorus]
Genetic genealogy, the family tree unfolds
Public databases tell the stories that DNA holds
Upload and compare, let the algorithms run
Cross-reference relatives till the guilty one is done
SNPs and markers, building bridges to the past
Finally justice found him, science solved it at last
[Bridge]
Third and fourth cousins, sharing common DNA
The algorithm narrows down, eliminating every day
Build a family tree backwards, find the common ancestor
Then trace forward through the branches, computational factor
[Verse 3]
GEDmatch held the key with open-source genetic code
Machine learning helped them walk the genealogic road
From millions down to hundreds, then to dozens, then to few
Till Joseph James DeAngelo emerged into their view
[Chorus]
Genetic genealogy, the family tree unfolds
Public databases tell the stories that DNA holds
Upload and compare, let the algorithms run
Cross-reference relatives till the guilty one is done
SNPs and markers, building bridges to the past
Finally justice found him, science solved it at last
[Outro]
Now forensic genealogy lights the cold case way
When DNA meets family trees, the guilty cannot stay
Hidden in the shadows of the crimes they thought were done
Science and technology, justice for everyone