John Kercher, the father of Meredith Kercher, the British college student whose brutal murder in Perugia, Italy, in 2007 made worldwide headlines, has died under mysterious circumstances.

The journalist of more than 40 years and the author of 24 children’s books was stoic in his grief as his 21-year-old daughter’s murder trial became one of the most sensational media frenzies in modern history. American Amanda Knox, Italian Raffaele Sollecito, and Ivorian Rudy Guede were all originally convicted of her murder. Knox and Sollecito were later released on appeal and Guede is expected to be released this year.

Kercher, who wrote a book about his daughter’s murder called Meredith in 2013, said the acquittal of Knox and Sollecito was devastating. “Hundreds of miles away from the center of the events, I sat stunned and open-mouthed,” he wrote. “To hear that they had been acquitted and exonerated of any blame in Meredith’s death was staggering.”

The 77-year-old, who suffered a stroke in 2009 that kept him from attending much of his daughter’s murder trial, was found with devastating injuries, including a broken arm and leg, outside his home in Croydon, England, on Jan. 13. The Sun newspaper reports that he had no recollection of what happened to him when he was found just yards from his home around 7:30 p.m. on a misty evening. He died in a hospital from his injuries last weekend after reportedly slipping into a coma.

Police are asking for leads and information to determine exactly who is responsible for Kercher’s injuries, which led to his death. While they are initially working on the theory of a hit-and-run vehicular accident, they have not ruled out that he could have been intentionally hit or even beaten up.

Met Police Det. Sgt. Steve Andrews told local reporters the incident is under investigation. “Despite thorough inquiries made so far, including speaking to witnesses and examining potential CCTV opportunities, we have not as yet been able to establish how he came to sustain his injuries, which included a broken arm and broken leg,” he said. “We are keeping an open mind as to the circumstances of his death, including whether he may have been involved in a collision.”

Over the years, Kercher told The Daily Beast that he was not satisfied with the outcome of the final trial and felt personal pain over Knox’s rise to stardom over the high-profile trials, which lasted for nearly a decade. Knox, who recently posted a photo on Instagram in her old prison garb for reasons not yet clear, has not publicly commented on the death of her former roommate’s father. She had previously expressed interest in meeting them, but they refused any such encounter.

The Seattle native has maintained a high profile as an advocate for wrongfully convicted people. She returned to Italy for the first time last summer to speak at an event sponsored by the Innocence Project.

The Kercher family released a statement confirming the death: “We loved him dearly and he is going to be very sorely missed.”

Editor’s note: Barbie Latza Nadeau is the author of Angel Face: Sex, Murder and the Inside Story of Amanda Knox, which was adapted for film in 2014.