Police arrested Maison Des Champs, an anti-abortion activist known for his climbing stunts, for scaling the tallest building in Oklahoma on Tuesday morning, NBC News reports. Des Champs has previously climbed The New York Times building in New York and the Salesforce Tower in San Francisco. Oklahoma City police said they weren’t sure why Des Champs was scaling the Devon Tower, a 50-story skyscraper in downtown Oklahoma City. On his Instagram, where Des Champs calls himself the “pro-life Spider Man,” he posted videos of him climbing the tower Tuesday morning. KFOR reported that he also streamed his ascent and that he climbed it using only chalk for his hands and no other gear. Police arrested him at the top on suspicion of trespassing and disorderly conduct, and he is was in police custody on Tuesday afternoon.