Twenty states have enacted laws restricting rights to peaceful protest, as environmentalists are increasingly criminalized

The shooting of Manuel Esteban Paez Terán, believed to be the first environmental defender killed in the US, is the culmination of a dangerous escalation in the criminalization and repression of those who seek to protect natural resources in America, campaigners have warned.

The death of the 26-year-old, who was also known as “Tortuguita” or “Little Turtle,” in a forest on the fringes of Atlanta was the sort of deadly act “people who have been paying attention to this issue assumed would happen soon, with no sense of joy”, according to Marla Marcum, founder of the Climate Disobedience Center, which supports climate protesters.

A photo of Manuel Esteban Paez Terán, who was shot and killed by a Georgia state trooper, on a makeshift memorial in Weelaunee People’s Park in Atlanta. Photograph: The Washington Post/Getty Images

“The police and the state have a callousness towards the lives of those on the frontline of environmental causes and I hope this is a wake-up call to those who didn’t know that,” she said. “I hope people take the time to notice what’s going on, because if this trajectory of criminalization continues, no one is going to be safe.”