What sort of person could watch a woman being stabbed to death and do nothing to help her? What if not one, but an entire crowd, responded to such gruesome violence with indifference? What kind of a place would allow such things to happen?

America has been grappling with the implications of Kitty Genovese’s murder ever since it took place on March 13, 1964. The world was shocked to read in the New York Times that 38 witnesses watched the murder take place and made no effort to help. Only one such bystander called the police, and only after Kitty had died. For half a century, the “urban apathy” that allegedly allowed this murder to take place has been a source of curiosity and outrage.

The theme of urban apathy, though certainly present, is not at the heart of James Solomon’s new documentary, The Witness, which follows Kitty’s younger brother Bill Genovese on his quest to discover, 40 years later, what really happened that night in Kew Gardens, Queens.

Mr. Genovese’s research is thorough and evidence he uncovers is compelling, but The Witness is much more than a crime investigation film. It is, primarily and most powerfully, the story of an individual’s quest to finally find healing after a great tragedy and his belief that in order to find peace, he must find the truth.

“No one understood me like Kitty,” Mr. Genovese, who narrates the film, proclaims early on. He was 16 when Kitty was killed; she was 28. For Mr. Genovese, the implications of that night, and of the story nearly everyone believes about it, have remained with him through the decades. Perhaps the most dramatic consequence is the loss of his legs in the Vietnam War. Mr. Genovese does not hesitate to connect his enlistment into the Marines with what happened to his sister, citing his determination not to be an “apathetic bystander.”

“The choices that he made in his life were all related to the fact that no one helped his sister,” his wife explains.

However, as his investigation progresses, Mr. Genovese begins to discover that the story he grew up with and, in a sense, shaped the narrative of his life, may not have been so accurate. He tracks down witnesses or their family members, who give him stories that are a far cry from what the New York Times reported in March of 1964.

At this juncture the film explores interesting territory on two fronts. First, it forces viewers to grapple with the reliability of these people’s memories. The film doesn’t tell us conclusively whether or not the witnesses are telling the truth; we must decide for ourselves if we are going to believe them. At one point, Mr. Genovese asks about a woman who claims to have called the police, “Did the police fail to log the calls, or did Hattie just create a story she could live with?”

Additionally, the film also explores the tangled world of journalistic ethics. As Mr. Genovese tries to figure out why other newspapers didn’t question the accuracy of the New York Times report, the Times’ clout is referenced repeatedly. Abe Rosenthal, who was the editor of the Times when the murder took place and who later wrote a book about it, appears on screen for an interview during which he says that he can’t “swear to God” there were 38 people, but that the story “did something. And I’m glad it did.”

Did the Times’ misreport work out for the best? Is America a better place because of the effects of misleading reporting? These questions are likely to remain up for interpretation and debate.

Several of Kitty’s nieces and nephews appear on screen. They say that Kitty’s death eclipsed her life in their family’s retellings and that their parents never really told them anything about what she was like. Mr. Genovese himself doesn’t know much about her either outside of the mystery surrounding her death. The Genovese family moved to Connecticut when he was a child, and Kitty stayed behind in New York City. Towards the end of the film, a large part of Mr. Genovese’s investigation in focused not on his sister’s death, but on her life in New York City. In a way, this feels like moving on. Or at least taking a step in the right direction.

“It’s hard to let go when you can never know the whole truth,” Mr. Genovese says. But Mr. Genovese—and the audience—knows more about Kitty at the end of the story than he did at the beginning, and he knows that she didn’t die alone. That has to count for something.

Dean Graham is a student at The King’s College. He serves as editor-in-chief of The Troubadour and a contributor for The Empire State Tribune. Find him on Twitter @deangrahamiii