With the UPV a spent force following Doherty's jailing, Mitchell joined the UVF sometime in the late 1960s. Soon after Mitchell joined the UVF, the socio-religious and political conflict known as The Troubles broke out with an explosion of violence from both sides of the religious/political divide. As a consequence the UVF became much more active as violence escalated on both sides. Mitchell rose through the ranks to become one of the senior figures within the movement and was a member of its Brigade Staff (Belfast leadership). He also served as editor of the UVF magazine "Combat". When writing for "Combat" he used the pseudonym 'Richard Cameron' which he took from one of his idols the Scottish Covenanter of the same name. However, by 1973 Mitchell had become weary of the constant struggle and became one of the main advocates within the group for a ceasefire and attempts to build a resolution. Like many loyalists of his generation Mitchell had been of the belief that the Troubles would be short and that the republicans would be defeated fairly quickly but this had not proven to be the case.