It started with the theft of a piggy bank containing $50 in coins.

That burglary at a home on West Walnut Avenue in the small California city of Visalia in March 1974 was the beginning of a 12-year reign of terror.

Over the years police concluded the Visalia Ransacker was the same person as the East Area Rapist and the Original Night Stalker - a catalogue of crimes merged together as the work of the Golden State Killer.

Suspected of at least 12 murders, more than 50 rapes and more than 100 burglaries, the hunt for Golden State Killer consumed police for 44 years.

But the arrest of 72-year-old Joseph DeAngelo last week, on suspicion of being responsible for those crimes, was significant in ways that could change investigations forever.


The confirmation that police uploaded old crime scene DNA to a publicly-accessible genealogy website and then traced a family tree to locate a suspect is raising questions about privacy and ethics.

Even the law enforcement agencies involved in the arrest seem uncertain about where this leads.

"You know there's going to be discussions about privacy and the public nature of these databases, like there is on everything, and that is fine," said Sacramento County Sheriff Scott Jones.

"Those are discussions for other people to have.

"Our need is to solve crimes and bring offenders to justice and give justice to victims, which is what we did here."

Image: Police used an open source database called GEDmatch

As with the discussion about how much control we have of data we choose to share online, the case has revealed a world of unexpected consequences to our desire for connection.

Police used an open source database called GEDmatch, a collection of almost a million DNA files which consumers voluntarily uploaded having sought from commercial testing companies like ancestry.com and 23andme.

But where investigators would need a court order to access data from those commercial testing firms, there are no restrictions on using public databases.

GEDmatch made no secret of this, saying: "While the database was created for genealogical research, it is important that GEDmatch participants understand the possible uses of their DNA, including identification of relatives that have committed crimes or were victims of crimes.

"If you are concerned about non-genealogical uses of your DNA, you should not upload your DNA to the database and/or you should remove DNA that has already been uploaded."

Last year, the Golden State Killer detectives had accessed a different genetic website while investigating a man they wrongly believed to be a suspect.

Regardless of whether DeAngelo is convicted, one of the most notorious criminal cases in American history could have far-reaching implications for police work.

As if to prove the point, it was revealed this week that detectives hunting another notorious California murderer, the Zodiac Killer, are also using DNA and family trees in the hope of a breakthrough after decades of searching.

:: Golden State Killer: Unmasked begins on Sky Living tonight at 9pm