When artist Clayton Conner starts working on his murals, onlookers sometimes mistake them for graffiti.

For the first few days, the dots, blurs and lines – that later manifest as intricate scenery or characters – alarm residents, often prompting them to call the police, Conner said. “They’re like, ‘Oh my God, I’m going to call the cops. Someone is graffitiing this.’ Then they see the images emerge and realize it’s actually someone who knows what…