The true story behind Netflix's The Breakthrough, explored

The Breakthrough is a Swedish true-crime series about a double murder case. It was released on Netflix on January 7, 2025. Directed by Lisa Siwe, this mini four-episode series explores the details of the case thoroughly and explores new ways that have been developed to solve a crime.

Based on the 2004 Linköping murders in Sweden, The Breakthrough follows a detective and a genealogist who solve a 16-year-old cold case using advanced DNA testing and genealogical research.

The series dramatizes the first use of such methods in Swedish criminal investigations, highlighting the transformative impact of technology and teamwork in forensic science.

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How did innovative DNA techniques help solve the case in The Breakthrough?

A still from the series (Image via Netflix)

In The Breakthrough, the most crucial part of the investigation came into play when a detective got together with a genealogist so they could use the most recent DNA analysis. As noted by FSIgenetics, such joint efforts with a genealogist marked the first instance in Europe where genealogical research was found to help solve a murder case.

Detectives used international genealogical databases and DNA evidence to trace the suspect's family tree back nine generations. They relied on historical records, including church documents and death notices, to piece it together.

The culmination of this research led to the identification of two brothers, one of whom was confirmed as the killer through direct DNA comparison. This innovative approach not only resolved a 16-year-old cold case but also set a precedent for using genealogical DNA analysis in criminal investigations, demonstrating its potential to uncover leads where traditional methods have failed.

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Is Stina Eriksson a real journalist?

A still from The Breakthrough (Image via Netflix)

In The Breakthrough, a journalist named Stina Eriksson, working for the fictional Swedish newspaper Ostgota Correspondenten, plays a significant role. By the series' conclusion, Stina is disclosed to be a cousin of the murderer, adding a dramatic twist. However, Stina Eriksson is not a real person. Her character may be loosely inspired by Anna Bodin, a real-life journalist who has reported for Dagens Nyheter since 1998 and co-authored the book The Breakthrough with Peter Sjölund, which served as source material for the series.

While the show dramatizes her meeting Peter at one of his conferences to collaborate on the book, there is no direct evidence this occurred exactly as portrayed. Stina’s character is a fictionalized narrative device, blending real-life inspiration with creative storytelling.

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Who was identified as the killer?

Daniel Nyqvist was identified as the killer behind the 2004 double murders in Linköping. According to The Guardian, Nyqvist confessed to the crime shortly after his arrest in June 2020. After being arrested, he later confessed that he had no prior links with any of the victims and that the attacks were unprovoked.

As reported by The Local, he disclosed that he had constantly heard voices inside his head, Nyqvist admitted in court that the murders were unprovoked and that he heard voices telling him to kill someone to find peace of mind. Nyqvist's solitary lifestyle and lack of criminal record helped him manage to avoid detection for 16 years.

His arrest and subsequent confession brought closure to one of Sweden's most bizarre cold cases. It also highlights the effectiveness of combining genealogical research with traditional police work.

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Stay tuned for news and updates, and catch The Breakthrough streaming on Netflix.