Dennis Johnson
Cassidy, who played guitar, helped form D.R.I. in 1982 when he was 21 years old, along with his friend Kurt Brecht, Kurt's brother Eric Brecht on drums, and Dennis Johnson on bass. After releasing their first album in 1983, D.R.I. experienced its first lineup change, with Eric and Dennis Johnson leaving the band in 1984. Since then, D.R.I. would go through many lineup changes, although Cassidy has remained constant as the guitarist alongside vocalist Kurt Brecht who also has been an all time permanent member.