Actors Brad Pitt and Leonardo DiCaprio have come under fire for signing onto a Quentin Tarantino film about the 1969 murder of Sharon Tate.

The late actress’ sister, Debra Tate, told TMZ that Pitt, 54, and DiCaprio, 43, are “throwing their responsibilities to the wind” by starring in “Once Upon a Time in Hollywood.” The upcoming Tarantino film will focus on an actor who lives next door to Sharon Tate at the time of the 1969 slayings.

“To [celebrities] it’s a paycheck and these people just don’t care. They are terribly hurtful to the actual family and all the living victims. They don’t give a s**t,” she told the tabloid.

In a statement issued to USA Today, Tarantino describes the film as “a story that takes place in Los Angeles in 1969, at the height of hippy Hollywood. The two lead characters are Rick Dalton [DiCaprio], former star of a western TV series, and his longtime stunt double Cliff Booth [Pitt]. Both are struggling to make it in a Hollywood they don’t recognize anymore. But Rick has a very famous next-door neighbor…Sharon Tate.”

Tarantino said the movie was five years in the making and noted that he was seven and living in Los Angeles in 1969, when the murders took place.

Debra Tate said she’s sure that Tarantino’s latest project will glorify Charles Manson, who died in November at age 83, as he has a penchant for romanticizing murder in his movies.

According to Fox News, Margot Robbie, 27, is rumored to be portraying Sharon Tate in the upcoming film.

[Featured Image: Brad Pitt/Evan Agostini/Invision/AP; Leonardo DiCaprio/Vianney Le Caer/Invision/AP]