In January 2015, Carl-Fredrik Arndt and Peter Jonsson, two Stanford University graduate students, stumbled across a man on top of a woman behind a campus dumpster. The man in question was Brock Turner, and once Arndt and Jonsson realized he was sexually assaulting an unconscious woman, they decided to act.

On June 3, 2016, BuzzFeed published the powerful letter the victim read aloud to her attacker on the day of his sentencing. Her striking words prompted Arndt and Jonsson to speak out about that night's events.

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Arndt and Jonsson said they were bike riding the night of the incident near the Kappa Alpha fraternity house when they found Turner, 20, on top of the victim.

"We saw that she was not moving, while he was moving a lot," Arndt told the news outlet the Expressen in Swedish, which was then translated by BuzzFeed News. "So we stopped and thought, 'This is very strange.'"

Both students then went over to Turner to see what was happening.

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“When he got up we saw that she still wasn’t moving at all, so we walked up and asked something like, ‘What are you doing?’” Arndt said.

Arndt said Turner ran away from him and his friend, so Jonsson went after him.

Arndt said they were able to hold Turner down until police arrived.

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Turner was charged with three felonies: assault with intent to commit rape of an intoxicated woman, sexually penetrating an intoxicated person with a foreign object, and sexual penetration of an unconscious person. Turner was found guilty. Judge Aaron Persky gave Turner a six-month jail sentence.

In the victim’s letter, she mentions how grateful she is for Arndt and Jonsson doing what they did to help her.

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"Thank you to the two men who saved me, who I have yet to meet," the victim wrote in her 12-page letter "I sleep with two bicycles that I drew taped above my bed to remind myself there are heroes in this story. That we are looking out for one another. To have known all of these people, to have felt their protection and love, is something I will never forget."

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According Arndt's LinkedIn profile, he was earning his Ph.D. in computational and mathematical engineering  at the time of the incident. He was also a teaching assistant in math and engineering.

Jonsson shared the victim's letter on his Facebook page on Tuesday, urging everyone to read it.

“To me it is unique in its form and comes as close as you can possibly getting to put words on an experience that words cannot describe,” Jonsson wrote.

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