Keith Beauchamp is a young filmmaker who has dedicated 10 years of his life to telling the story of Emmett Till, the 14-year-old black boy brutally slain in Mississippi in the summer of 1955.
"It's my obligation to tell this story, as a young individual in this country, as a young person from my generation," Beauchamp said. "It's important that we never forget those that pave the way for us to exist in a free society."
Emmett Till was from Chicago. That summer, he had gone to the farmlands of Mississippi to visit family. One afternoon at a local store, Till allegedly whistled at a white woman. Later that night, the teen was dragged from bed and beaten to death. His body was dumped in the Tallahatchie River.
"Emmett Till's murder, Emmett Till's case was the catalyst of the American civil rights movement," said Beauchamp, 33. "It was because of him that young Martin Luther King decided to take on the Montgomery bus boycott. It was because of him that Rosa Parks decided not to get up from her seat that day."
As a child growing up in Baton Rouge, La., Beauchamp was told Emmett Till's story repeatedly.
"It was used as an educational tool in my household to teach me about racism that still lurks in these Americas," he said. "The first thing my parents would often tell me before I left the house at night was, 'Don't let what happened to Emmett Till happen to you.'"
Two men were arrested for Till's murder, but they were acquitted by an all-white jury that deliberated for only an hour. The men later confessed to the murder but were never punished.
At his funeral, Till's mother insisted that the coffin be left open. She wanted the world to see what had been done to her son. Years later while reading a magazine, Beauchamp came across a photo taken of Till in his casket. It changed his life.
"I saw myself in a way," he said. "And that's why that photograph is still so powerful today. Here you had a 14-year-old, innocent child that was murdered for a simple act of whistling."
Beauchamp began work on his film after moving to New York.
"The passion just took over me," he said. "There were times when I didn't have enough money to spend on myself to buy clothes, and I just felt guilty buying those things when I knew it could be going toward the film."
He traveled back and forth to Mississippi interviewing hundreds of people, including eyewitnesses to Till's murder.
"These people are still alive and no had ever talked to them," he said, "so they gave me the full story, and it was just strange at some point to think that you're the one that's holding this information and what are you going to do with it."
Beauchamp turned up evidence that could implicate as many as eight more people in Till's death -- five of whom are still living. His documentary, "The Untold Story of Emmett Louis Till," impressed the Justice Department enough to reopen the case.
Beauchamp said his thoughts are with Emmett Till's late mother.
"She fought for 47 years to see that justice take its rightful course in her son's murder," he said.
This week the Justice Department announced that Till's body would be exhumed and that an autopsy would be performed for the first time. Beauchamp may have helped solve a mystery buried for half a century.
"Justice must prevail in this case," Beauchamp said. "It must prevail to put hope back in the African-American community across this country. We have a long way to go. The civil rights movement still exists in this country. It has never ended."
ABC News' Elizabeth Vargas filed this report for "World News Tonight."