On Tuesday, Duff took to Instagram to share a selfie while still in costume, writing: "Had the incredible opportunity of playing Sharon Tate the past two weeks in an independent movie. She was an amazing woman and it was a true honor."
On Aug. 8, 1969, followers of Charles Manson murdered Tate -- who was pregnant at the time -- and five of her friends at her Hollywood home, while her husband, filmmaker Roman Polanski, was out of town. Tate was found stabbed 16 times with an "X" carved into her stomach. She was 26.
Prior to revealing her role in the indie flick, Duff shared a photo of herself wearing a faux baby bump. "Not really pregnant guys....just shooting a movie," she captioned the post.
Fascination around the Manson murders seems to be big in Hollywood as of late. In addition to The Haunting of Sharon Tate, Quentin Tarantino is also making an untitled Manson-related movie, and it was confirmed by The Hollywood Reporter this week that Matt Smith will portray Manson in Mary Harron's Charlie Says.
Manson died in November after being imprisoned for more than 45 years. He was 83.