Campbell has conducted homocide trials successfully in the Supreme Courts of Victoria and the Northern Territory. He has appeared in County Court trials since 1993. He has acted for claimants in major Native Title cases in the Federal Court and High Court including Ward v WA, Yarmirr v NT, and is acting in the Wotjobaluk mediation in Victoria. He has argued for environmentalists at VCAT and in the Supreme Court and is acting for defendants in the Gunns 20 litigation. He is working on an appeal concerning native title trusts in the High Court.