Sister June Wilkerson leans over to examine the tattoo on Marc Hoffman's chest. "This is going to be completely gone," she promises. Hoffman nods but is still concerned. "The one that says 'White Power' is doing pretty good," agrees Hoffman, 31, a former white supremacist, now a college student. But, he adds, pointing to the swastika on his right pec, "this is going to take a little longer."

Wilkerson's dedication to removing tattoos is more than skin-deep. At a community violence-prevention meeting near Los Angeles three years ago, the nun learned tattoos not only prevented people from finding jobs but also often led to attacks. That was all the nun needed to hear. With $25,000 in seed money and volunteer medical help, she founded a clinic in 1998 at the Providence Holy Cross Medical Center in Mission Hills that has helped 500 former gangbangers, hookers and others rid themselves of images of their former lives. "They say a leopard can't change its spots," says Daniel Medina, 54, an ex-con who now mentors juvenile prisoners, "but we are."

Still, Wilkerson's help comes at a price. Patients must either do community service or enroll in school. "No work, no removal, no exceptions," says Wilkerson, 76. Helping others transform their lives is a habit with the St. Louis native. After college, she joined the order of Sinsinawa Dominicans, a group founded by an Italian priest. Having spent most of her life teaching social studies, Wilkerson concedes that zapping tattoos may seem an unusual mission. Even so, it is an important one. "Removal," she says, "is about letting the outside reflect the inner change."