Justin Butler is a Shihan of the San Ten Karate organization under tenth-dan Hanshi Vincent Cruz.
Butler studied a mix of Shotokan and Hakkoryu jujutsu for fifteen years with Kaiden Master Dennis Palumbo. Palumbo awarded Butler his 1st, 2nd and 3rd dan certificates. After Palumbo retired, Butler received his 4th and 5th dan certificates from Hanshi Cruz. Palumbo also certified Butler in Koho Shiatsu, advanced pressure-point training for healing.
In August 2008, Cruz appointed Butler to be soke of the San Ten Jujutsu organization, charged with the task of reintegrating jujutsu and karate into one art.
Butler's dojo, Golden Eagle Shotokan, is located in Denver, Colorado.