Nicholas Celozzi has spent much of his life revisiting the events leading up to the assassination of former U.S. president John F. Kennedy.

Hushed stories filled his childhood home. Conversations with his uncle Joseph [Pepe] Giancana, brother to Chicago Mob boss Sam Giancana, later helped shed light on his family's possible involvement in one of the most debated moments in American history.

After decades of film and television portrayals of Sam Giancana, Celozzi is reconceptualizing the 1963 shooting of Kennedy with a focus on the major players in the Chicago Outfit, a powerful Italian-American criminal organization.

For Celozzi, his latest screenwriting endeavour is about more than telling another assassination story. It's about family.

"My family, my cousins, really got tired of people using our name, monetizing our name and telling a fake story," Celozzi said in an interview.

"These aren't fictional people ... they're real people. They're vulnerable, they have nerves, they make mistakes, they are not quite sure about things."

Sam Giancana, head of the Chicago Outfit in the 1950s and 1960s, was widely known for his ties to the Kennedy family. He was gunned down in his home in 1975, and his killing remains unsolved.

Many have speculated the mob group also played a role in Kennedy's assassination, and this is explored in Celozzi's November 1963, which began filming in Winnipeg this summer.

Relying on Pepe Giancana's stories, Celozzi focuses on the 48 hours leading up to the assassination.

Giancana, a fill-in driver for his brother, had been a fly on the wall in the days leading up to the assassination, said Celozzi, who is also one of the producers on the independent film.

Many conversations led to what Celozzi calls the "Pepe chronicles," a series of stories detailing the family's Mob ties.

"I was always aware of who they were. These aren't things that everybody just kind of goes home and talks about. It's an awareness. It's kind of a strange reality that you're born into," said Celozzi.

Pepe Giancana died in the mid-'90s, leaving his stories with Celozzi.

Drive for honesty

The writer said he knew he wanted to do something to honour his family's history without degrading them to caricatures often found in Mob flicks. So he began working with Sam Giancana's daughter Bonnie Giancana to craft the script.

Over the course of several years and rewrites, Celozzi said they worked to ensure every detail was accurate.

"I needed to keep that honest with the story Pepe gave me, or why do it at all? If I wasn't going to be truthful to what he gave me, there was no purpose in me doing it," said Celozzi.

He brought veteran Canadian producer Kevin DeWalt of Minds Eye Entertainment on board to produce the movie, which wrapped shooting in Winnipeg last week and goes into post-production in Saskatchewan.

"I don't think the family's proud of what happened ... it was important for them to tell the truth before they die," DeWalt said.

The cast includes John Travolta, Dermot Mulroney and Mandy Patinkin and is directed by Academy Award nominated English filmmaker Roland Joffe.

When it came time to pick a location that could mimic 1960s Chicago and the landmark Dealey Plaza in Dallas, where Kennedy was killed, producers chose Winnipeg over other major cities such as Atlanta and New Orleans in part because of its Exchange District neighbourhood. Producers decided Winnipeg was a perfect stand-in for the Windy City.

Dealey Plaza, and the famous Grassy Knoll, was built from scratch at Birds Hill Provincial Park, northeast of Winnipeg.

The film features 1,500 extras and 75 to 80 period cars to accurately portray the time period.

DeWalt said he expects viewers will be blown away by the film's ability to bring a new level of authenticity and validity to the moment in history.

"People will walk out of the theatre with their own impressions about what it all means," he said.

"At the end of the day, at least we've given them the tools for one of these things that's been told, and they can make their own impressions in terms of how they feel about it."

When asked if he thinks the film might ruffle feathers with historians, governments or Mob members, Celozzi said that's not his goal.

"What I'm doing is just putting in that missing piece, not glamourizing, just writing it."