Elsa is a criminal defence lawyer and the founder of Wyllie Law in Vancouver. She appears regularly in the BC Supreme Court and Provincial Court in serious criminal matters including murder, sexual offences, and drug trafficking, and has appeared at the Supreme Court of Canada as intervenor counsel on sentencing fairness to Indigenous and marginalised communities (R v Nahanee, 2022 SCC 37). She also practises as complainant counsel in sexual offence proceedings and acts in human rights matters before the BC Human Rights Tribunal.

Elsa is a partner at Arendt Chambers, where she practises international criminal law. She is currently counsel at the International Residual Mechanism for Criminal Tribunals (a UN Security Council subsidiary organ) and is engaged in advocacy before Security Council missions on behalf of stranded acquitted persons. She co-chairs the IBA War Crimes Committee’s annual conference at The Hague and has published in Opinio Juris on the institutional legitimacy of international tribunals.

She holds an LLM from Columbia University (Harlan Fiske Stone Scholar), an LLB (First Class Honours) from the University of Otago, and an MA (Distinction) in International Law and Security from the University of Birmingham. She supervises the UBC Law Innocence Project and guest lectures at law schools (most recently at UBC Allard School of Law and TRU Faculty of Law).