Two Swedish graduate students, Peter Lars Jonsson and Carl-Fredrik Arndt, were cycling on the Stanford campus at about 1:00 a. m. , on January 18, 2015, when they spotted the assault taking place. According to Arndt and Jonsson, they surprised Turner behind a dumpster as he was on top of an unconscious woman. Jonsson testified that he confronted Turner, asking, "What the fuck are you doing? She's unconscious. " According to Jonsson, Turner quickly rose and fled the scene. As Arndt briefly went to determine whether she was breathing, Jonsson chased Turner, tripped him and held him down around 75 feet (23 m) away from the dumpster, asking "What are you smiling for?" Later, responding to the assistant District Attorney's questions during the trial, Turner testified that he was laughing because he found the situation ridiculous. Arndt rapidly joined the chase, helping to pin Turner down when he was apprehended. A bystander at the dumpster called emergency services while two other passersby arrived to help Arndt and Jonsson keep Turner pinned on the ground. Campus police arrived moments later, questioned Turner, and then arrested him.