Devon Williams, A.K.A John Marcus of the Judgement Yard family was born in Rose Hill, St. Andrew.
He has been residing in August Town since 1988 where he has pursued his musical career as a DJ performing in the realms of the Judgement Yard family at various concerts.
Within Marcus' maturity in the musical world, he has come to realize his ability as a teacher in the Rastafari music. John Marcus has been assisting younger artistes in their career.
In his endeavor to assist the youths, John Marcus has opened up a studio in August Town called Chop Chop Recording Studio where he produces various artistes of the likes of Congo Judah, Norris Man, Sizzla Kalonji, and Shepherd and more. Marcus is now looking forward to establishing his producing ability internationally.