New Zealand legal history was made earlier this month when the Supreme Court allowed former Christchurch Civic Creche worker Peter Ellis's appeal against charges of sexual offending to continue, despite the fact he died in September last year. It will be the first time in Aotearoa that a conviction is appealed by a dead person. Counsel for Peter Ellis, Natalie Coates, used an argument based on tikanga - that both Maori and Pakeha have mana in death and if the appeal was successful, this would affect his mana and that of his whanau. Tikanga (Maori customary practice) is increasingly recognised in legislation and by the courts as important, but Ellis' appeal is being seen as a landmark case. So how and why should tikanga be woven into our legal system? Natalie Coates is a partner at Kahui Legal who's previously worked as a law lecturer at the University of Auckland, for her iwi, and at an international human rights organisation.