HBO's new three-part docuseries, 'A Killer Story,' directed by Matthew Galkin, chronicles the efforts of Pulitzer Prize-winning journalist Joe Sexton and citizen sleuths Eileen and Keen Umbehr to overturn the murder conviction of Dana Chandler. Chandler was sentenced to two life terms in 2012 for the 2002 murders of her ex-husband Mike Sisco and his girlfriend Karen Harkness.

The series opens with Sexton, working at ProPublica, receiving an anonymous tip that leads him into the complex case. The Umbehrs, true crime enthusiasts from Topeka, Kansas, where the victims lived, became convinced of Chandler's innocence, believing she was convicted without sufficient physical evidence. Eileen Umbehr, whom Sexton nicknamed "Pen Pal," engaged in a persistent correspondence, sending thousands of letters over two years before Sexton committed to investigating the case.

Despite the initial conviction, the legal journey for Chandler proved lengthy. Her conviction was overturned in 2018, but she faced three separate trials. The second trial resulted in a hung jury, and the third saw Chandler represent herself, which proved detrimental and led to a conviction.

'A Killer Story' delves into Chandler's initial trial, during which her two adult children testified against her. The case's progression to trial was delayed due to the district attorney at the time's belief that there was insufficient evidence to place Chandler, who resided in Denver, in Topeka on the day of the murders. However, a subsequent, more amenable district attorney initiated the arrest in 2011, leading to the trial.

The docuseries, narrated by Sexton, highlights the perceived flimsiness of the case against Chandler. The Kansas Supreme Court had previously admonished the prosecutor for misconduct. The series also portrays the Umbehrs not merely as casual observers but as determined individuals. Keen Umbehr, a former trash collector who became an attorney, had a history of advocating for the underdog, successfully arguing a freedom of speech case before the U.S. Supreme Court in 1995.

'A Killer Story' is noted for its brisk pacing, with each of the three episodes running under 40 minutes. While it examines Chandler's murder trials, the narrative also focuses on the connection forged between Sexton and the deeply religious Umbehr couple, avid followers of true crime. The series aims to explore how Sexton, the Umbehrs, and Chandler sought her exoneration and the circumstances that led Chandler to represent herself in her final trial. The Umbehrs reportedly believe not only in Chandler's innocence but also in the identity of the actual perpetrators.