In an interview with The Hollywood Reporter, the "Birds of Prey" actress, 33, discussed the ongoing legal battle that her 38-year-old brother continues to face after he was accused of staging a hate crime against himself in early 2019.
While she has avoided speaking publicly about the alleged incident, she maintains her sibling's innocence.
"It's been f--king painful, one of the most painful things my family's ever experienced," Jurnee said. "To love someone as much as we love my brother, and to watch someone who you love that much go through something like this, that is so public, has been devastating."
She added: "I was already in a very dark space for a number of reasons, and I've tried to not let it make me pessimistic. But everyone who knows me knows that I love my brother and I believe my brother."
Jurnee said that she and her family are "blessed to have a community of people who know him and know that he wouldn't do this."
Jussie temporarily moved in with Jurnee after she filed for divorce from her estranged husband, and she said at times, she looks at him in awe of how "strong" he can be.
These days, while awaiting a conclusion to the ordeal, Jussie is "staying creative, as creatives do," Jurnee revealed, "singing, writing, working on music."
Jussie's troubles began last year when he told police that two masked men attacked him as he was walking home in the early hours of Jan. 29, 2019. He said they made racist and homophobic insults, beat him and looped a noose around his neck before fleeing.
Weeks later, police alleged Smollett paid two friends to help stage the attack because he was unhappy with his salary as an actor on “Empire," a Fox series filmed in Chicago that follows a family as they navigate the ups and downs of the recording industry.
Smollett was then charged with making a false report, but the charges would be subsequently dropped with little explanation from prosecutors. Months after the stunning announcement, a judge appointed Dan Webb, a former U.S. attorney, to look into why those charges were dropped.
Then, in February, Smollett was indicted again. He pleaded not guilty to the renewed charges brought against him and offered a rare public statement at the time, in which he maintained his innocence.
The Associated Press contributed to this report