Asunta Fong Yang was just 12 years old when she was killed by her adoptive parents, in a horrifying case that shocked the world.

To this day, questions remain about why her parents did what they did, about why the people supposed to protect her could in fact harm her. It’s an ongoing mystery, one Netflix addresses in its new series, The Asunta Case.

Starring Candela Peña and Tristán Ulloa, the six-part series is a dramatised account, but at its heart is a tragic real-life case, one that sent shockwaves across Spain. It tells the story of Asunta, who is remembered as a high-achieving, talented child.

The youngster, who grew up in Santiago, Spain, was adopted from China when she was nine months old. Her adoptive parents, Rosario Porto and Alfonso Basterra, a lawyer and journalist respectively, were both wealthy and well-connected in their city.

Like many children, Asunta was passionate about her hobbies which included ballet, violin and piano, and she was taking private lessons in multiple languages. In many ways, everything appeared as normal, but as we now know, something was terribly wrong.

On 21 September, 2013, days before her 13th birthday, Asunta’s parents reported her as missing. A few hours later, her body was discovered on the side of the road close to the town where she lived.

Who killed Asunta?

Both of Asunta’s parents were arrested shortly after her body was found when police investigating the case found their statements did not add up. Porto, it was discovered, had lied to police about her movements on the night of her daughter’s death, and police suspected Basterra’s involvement.

The pair were put on trial in October 2015, and both adoptive parents were found guilty of murder by a jury. Porto and Basterra, were sentenced to 18 years in prison. Their daughter had died of asphyxiation and had been given a high dose of Lorazepam pills (usually used to treat anxiety) on the day of her death, the coroner ruled. Reportedly, the dose was nine times higher than what would be given to an adult. It was also found the child had been ingesting smaller doses of the medication for months before her death.

What happened to Asunta’s family?

Over the years, Asunta’s parents both maintained their innocence. Porto made multiple suicide attempts following the sentencing and took her own life in November 2020. Basterra continues to serve his sentence in prison in Spain.

In the years since, much has emerged about the family’s seemingly perfect life. We now know that Basterra was violent toward his wife, and their marriage had frayed. The couple divorced a few months before murdering their daughter, and in the months prior, Porto, who had struggled with her mental health, lost both of her parents – prompting all public speculation about Asunta’s cold-blooded killing. But to this day, a motive has never been established.