Ruffalo, 48, joined Spotlight director and co-writer Tom McCarthy, co-writer Josh Singer and members of SNAP, the Survivors Network of Those Abused by Priests, at the Cathedral of Our Lady of the Angels in downtown Los Angeles Sunday to call for the names of priests accused of pedophilia to be released, according to The Hollywood Reporter.
Ruffalo is nominated for Best Supporting Actor for his portrayal of Mike Rezendes, a member of The Boston Globe's Spotlight team, whose meticulous reporting to uncover the scandal is dramatized in the film up for Best Picture.
The actor and activist confirmed his participation in the protest Sunday on Twitter.
"Standing with the survivors of Priest sexual abuse!" he wrote just hours before he was set to walk the Academy Awards red carpet.
Standing with the survivors of Priest sexual abuse! https://t.co/xfV9bV5m3q— Mark Ruffalo (@MarkRuffalo) February 28, 2016
Later, he shared an image of a flier seemingly handed out at the protest.
"Just got back from a protest with SNAP Priest Sexual Abuse Survivors," he captioned the Instagram shot.
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Last month, Ruffalo told PEOPLE he's proud of the way the film handles the delicate subject matter in "a really mature, serious way."
"The other thing that's amazing about the movie is that it's really a celebration of journalism and the power of it," Ruffalo also said. "I think it reawakens us. It reawakens our appreciation of it."