D.I. is a Southern California punk band featuring ex-Adolescents and Social Distortion drummer Casey Royer on vocals. Royer formed the group after he and former Social Distortion original member Rikk Agnew (also formerly of Christian Death), left the original Mike Ness Social Distortion crew.Since forming in 1981, D.I. has had many line-up changes and Royer has been the only constant member of the band.