The sinister true story behind Netflix’s The Asunta Case

Here’s the true story behind the Netflix crime series The Asunta Case, including what happened to Asunta Yong Fang and her adoptive parents, Rosario Porto, and Alfonso Basterra.

Netflix continues to be the leading streaming service in true crime, with 2024 releasing numerous hits such as What Jennifer Did and Unlocked: A Jail Experiment. 

The Asunta Case is a dramatization of real events, centering on a murder that shocked Spain in the 2010s. 

Here’s everything you need to know about the sinister true story behind The Asunta Case, as well as who plays who in the Netflix show’s cast. Warning: Some may find this content distressing. 

The Asunta Case true story explained 

The Asunta Case on Netflix is based on the true story of Asunta Yong Fang, an adopted girl who was killed in 2013 at age 12 from asphyxiation.

Her adoptive parents, Rosario Porto and Alfonso Basterra, were found guilty of the crime, with the court ruling that the former couple had been drugging their daughter with Lorazepam in the months leading up to her death.

Various factors contributed to the case becoming one of the most significant and widely followed criminal trials in Spain.

Another reason the case became so high-profile was due to the parents’ wealth and social status. Rosario came from a prominent Galician family, having followed in her father’s footsteps to become a lawyer. Alfonso, meanwhile, was a journalist. 

The history of the case

It started in 2001, when Rosario and Alfonso traveled to Yongzhou, China, to adopt their nine-month-old daughter, Asunta. She was the first Chinese child ever adopted in Santiago, Spain. 

They lived an affluent lifestyle in the city and got married in 1996.

As Rosario suffered from an autoimmune disease, she was advised against pregnancy, and so the couple decided to adopt.

Asunta would grow up to be a bright girl, skipping a year at school and studying various languages. She trained in ballet, piano, and violin in her free time,

However, in the early hours of September 22, 2013, the tranquility of the Santiago community was shattered when Asunta was found dead in a wooded area near a country house owned by her family.

Her body was discovered by a passerby, tied with orange twine.

The discovery sent shockwaves through the city, sparking a massive investigation to uncover the truth behind her death.

The night prior, her adoptive parents had reported Asunta missing, presenting themselves as concerned. But on September 24, Rosario was arrested and under investigation, with Alfonso arrested a day later. Detectives initially noticed the mother’s suspicious behavior.

When they went to the country house to search the potential crime scene, she told officers that she needed to use the bathroom. But she was caught attempting to retrieve the orange twine Asunta’s limbs could have been tied in from inside a wastepaper basket. 

Forensics couldn’t determine if this was the same twine used on Asunta. However, this was just one piece of a complex puzzle.

Detectives also obtained CCTV footage showing Rosario driving towards the country house with a long-haired girl beside her. The time of this was at a period when Rosario had claimed her daughter was at home.

Additionally, the coroner determined that Asunta had been given at least 27 Lorazepam pills on the day of her death. Hair strand tests showed she had been given it periodically in the three months leading up to her death.

Lorazepam is a benzodiazepine that causes drowsiness — and it’s the main active ingredient in Orfidal, which Rosario had been taking for anxiety.

During the trial, it was revealed that Alfonso had obtained 175 Orfidal pills over 10 weeks.

Asunta’s teachers testified she had appeared drowsy in the weeks prior to her death, with one witness claiming she said, “My mother is trying to kill me.”

Although the parents maintained their innocence, the prosecution put forward the theory that Rosario and Alfonso had grown tired of caring for Asunta and started experimenting with drugging her before carrying out her murder.

Rosario, who had been struggling with depression and the death of her parents, is believed to have masterminded the plan. 

Many other factors contributed to the disturbing theory, including the couple’s divorce, which unfolded in January 2013 after Alfonso discovered Rosario had been cheating.

The criminal trial

Following a highly publicized trial in 2015, they were both found guilty of Asunta’s murder and sentenced to 18 years in prison.

In 2016, the verdict underwent revision, which concluded that there was insufficient evidence to establish Alfonso’s presence in the car with the mother.

Consequently, it was determined that the mother was responsible for the asphyxiation, but Alfonso’s sentence remained unchanged, as he was still considered to be involved in the planning and facilitation of the murder.

Where Rosario Porto and Alfonso Basterra are now

Following several attempts, Rosario died by suicide in her prison cell in November 2020. Alfonso is currently serving his sentence at the Teixeiro prison in Spain.

Although both Rosario Porto and Alfonso Basterra appealed to have their sentences overturned, these were denied.

According to the country’s prison system, Alfonso will be eligible for what’s known as an “open regime” in 2025, after serving two-thirds of his sentence. This essentially means that he’ll have more freedom and privileges, although he’ll still remain behind bars for the full 18 years. 

El Correo reported that he sent a letter to the producers of a documentary on the Asunta case in 2017, writing: “When I regain my freedom, I have the firm intention of disappearing, no one will hear from me again, not even Rosario Porto. I only have one reason to stay alive, which is none other than to be a free man again and reunite with my girl, never before. In fact, I’ve already thought about how and where, I just don’t know when, but everything comes [eventually].”

Who’s in Netflix’s The Asunta Case cast?

The cast of The Asunta Case sees Candela Peaa playing Rosario Porto. Meanwhile, Tristan Ulloa plays Alfonso Basterra and Iris Wu plays Asunta Fong Yang Basterra Porto.

Other cast includes: 

• Javier Gutierrez as Judge Malvar
• Maria Leon as Agent Cristina Cruces
• Carlos Blanco as Agent Javier Ríos
• Francesc Orella as Juan Jose Dominguez
• Raul Arevalo as Rodrigo Maneiro

Candela Is best known for Hierro, Take My Eyes, and All About My Mother. Meanwhile, Tristan has appeared in Berlin, Warrior Nun, and the Snatch TV series. 

The Asunta Case is streaming on Netflix now.

For more true crime, check out the new documentaries streaming this month. You can also find more TV shows streaming, as well as new movies to add to your watchlist.