Atlanta, Georgia (CNN) -- Turn back time, more than 90 years, to a cold case that won't gather dust.



It's a classic whodunit, starting with the rape and murder of a 13-year-old girl and ending in a lynching. It was grist for a prosecutor's political aspirations, a case that was appealed all the way to the country's highest court and a story hotly debated in the national press.



At the center of it all was Leo Frank, a northern Jew who'd moved to Atlanta to supervise the National Pencil Company factory. When the body of Mary Phagan, a white child laborer, was found in the basement, law enforcement homed in on Frank. He was tried and convicted, based on what most historians say was the perjured testimony of a black man, and sentenced to death. But when the governor commuted his sentence in 1915, about 25 men abducted Frank, 31, from the state prison and hung him from a tree in Marietta, Georgia.



Considered one of the most sensational trials of the early 20th century, the Frank case seemed to press every hot-button issue of the time: North vs. South, black vs. white, Jew vs. Christian, industrial vs. agrarian.



In the years since, it has inspired numerous books and films, TV programs, plays, musicals and songs. It has fueled legal discussions, spawned a traveling exhibition and driven public forums.



Who murdered Mary Phagan? What forces were behind the lynching of Frank? Why should we still care?



Answers to these questions, or theories, keep coming.



"Leo Frank was not a good ole Southern boy. He was different and not ashamed of being different," said Ben Loeterman, whose new documentary, "The People v. Leo Frank," will air Monday on PBS. "The test of us as a society is not necessarily how we treat the best among us but how we treat the most questionable."



Mixed in with ongoing analysis of the Phagan-Frank story are the descendants of those involved, people who learned of their connections differently and carry these legacies forward in unique ways.



The accused



"The story goes that no one in my family talked about it," said Cathee Smithline, a 62-year-old great-niece of Frank.



Frank was the one who handed Mary Phagan her check when she stopped by the factory on April 26, 1913, Confederate Memorial Day. The night watchman, Newt Lee, would find the body and call police early the next day.



Smithline, of Wyckoff, New Jersey, was 16 when she first heard about the case. Her mother sat her down, told her a story about what a man in the South had been through, said it was based on her uncle and handed over a book: "A Little Girl is Dead."



It turns out Smithline's mother got the news in her teens, too, when her boyfriend turned to her after seeing "They Won't Forget," a 1937 Hollywood film. "You know that's about your uncle," he said.



She'd grown up hearing Uncle Leo died of pneumonia, and after asking family about it, the truth was revealed, followed by the words, "We will never talk about this again," Smithline said.



"I think it was a family embarrassment," she said. "My grandmother [who died when Smithline was 1] was very close to her brother. It cannot be easy to tell someone your brother was lynched and why."



The first victim



Mary Phagan Kean was 13 when the story hit her. She was in a South Carolina classroom, and her name stopped short a teacher taking attendance.



"Mary Phagan, you say?" she recalled the teacher asking, peering up from his list. He wanted to know if she was related to a girl with that name who died in 1913. Confidently, she told him she wasn't. But the boys on the playground taunted her anyway, telling her she was reincarnated from a dead girl
When was Phagan murdered? Who was convicted of her murder Who was murdered in 1913? What year was Mary Phagan's murder Who was convicted? What hot buttons did the case hit
April 26, 1913, Leo Frank, Mary Phagan 1913, Leo Frank, North vs. South, black vs. white, Jew vs. Christian, industrial vs. agrarian.
question: When was Phagan murdered?, answer: April 26, 1913, | question: Who was convicted of her murder, answer: Leo Frank, | question: Who was murdered in 1913?, answer: Mary Phagan | question: What year was Mary Phagan's murder, answer: 1913, | question: Who was convicted?, answer: Leo Frank, | question: What hot buttons did the case hit, answer: North vs. South, black vs. white, Jew vs. Christian, industrial vs. agrarian.