Two teenage girls set out for an afternoon walk on a February day in 2017 and never came home. The discovery of Abigail "Abby" Williams and Liberty "Libby" German's bodies in a wooded area near the Monon High Bridge in Delphi, Indiana, would spark one of the most closely followed criminal investigations in recent U.S. history—and now, a trilogy of documentaries exploring how law enforcement identified and charged a local man for their murders.

The crime itself became notorious for the evidence preserved on Libby German's phone: a grainy photograph of a man on the bridge and an audio recording of a male voice saying "down the hill." These fragments would become central to the investigation, offering investigators and the public alike tantalizing clues about the person responsible.

**Three Documentaries, One Case**

Hulu has committed significant resources to exploring the Delphi case through multiple angles. *Down the Hill: The Delphi Murders*, available as a two-episode series, covers the 2017 murders and the investigation as it stood roughly four years later, emphasizing the critical evidence recovered from the victim's phone.

A second series, *IMPACT x Nightline: Who Is The Delphi Killer?*, takes a more focused approach, examining whether Richard Allen—a local resident arrested and charged with the murders—is indeed the man in the photographs and audio recordings. The series covers his trial for the deaths of the two teenagers.

Most recently, Hulu premiered *Capturing Their Killer: The Girls on the High Bridge* on August 5, 2025. This three-episode documentary zeros in on Richard Allen as the accused killer, exploring the fear and mistrust that gripped Delphi and the dark secrets the small town harbored. Promotional materials state that the series documents how investigators "proved Richard Allen was bridge guy"—referring to the unidentified figure in Libby German's photograph.

**The Investigation and the Arrest**

For years after the murders, the case remained unsolved, with investigators and amateur sleuths scouring the bridge photo and audio for clues. The breakthrough came with Richard Allen's arrest, transforming the case from an active mystery into a criminal prosecution. Presented as a local man living in the community where the crimes occurred, Allen's arrest suggested that answers might finally be within reach for the families and the residents of Delphi who had lived under the shadow of unsolved violence.

**A Town in Focus**

Beyond the forensic and investigative elements, these documentaries offer something equally compelling: a portrait of a small American town confronting tragedy and suspicion. Delphi, Indiana, became synonymous with the case, and the residents' experiences—their fear, their speculation, and their hope for justice—form a crucial backdrop to the narrative. The Hulu series promise to explore not just the crime itself but the community's journey through investigation, arrest, and trial.

**What the Series Reveal**

While the documentaries vary in scope and focus, collectively they trace the arc from crime scene discovery through the presentation of evidence linking Richard Allen to the murders. Viewers gain access to the phone evidence that first captivated the public, interviews with investigators and community members, and the legal proceedings that followed Allen's arrest.

For international audiences following major American crime cases, the Delphi documentaries represent a significant media undertaking—three separate series on a single case, reflecting both the case's notoriety and the public's enduring fascination with unsolved murders in small-town America.

**Sources**

https://www.hulu.com/series/down-the-hill-the-delphi-murders-86deaccc-10f3-480b-bcb5-52d23e3b433f

https://www.hulu.com/series/impact-x-nightline-who-is-the-delphi-killer-3b968a2d-f62e-4f53-aa76-432e02da20f1

https://www.hulu.com/series/capturing-their-killer-the-girls-on-the-high-bridge-e9e92734-94f1-4c70-8287-da305d105147