David Cole was called to the Ontario bar in 1975. He then practised as a defence counsel for sixteen years, specializing in legal issues relating to prisoners and parolees. Judge Cole was appointed to the Ontario Court of Justice in 1991. From October 1992 to 1996, he was seconded to act as co-chair of the Commission on Systemic Racism in the Ontario Criminal Justice System. Over the period 2018-20, he has been seconded to conduct an independent review of the use of segregation in Ontario's correctional facilities, with particular attention to the issues confronting mentally ill prisoners detained on remand or after sentencing. Judge Cole has taught sentencing courses at the University of Toronto Faculty of Law; Osgoode Hall Law School, York University; and the Centre for Criminology, University of Toronto. He is the co-author of Release from Imprisonment: The Law of Sentencing, Parole and Judicial Review (Carswell, with A Manson, 1991) and the co-editor of Making Sense of Sentencing (University of Toronto Press, with JV Roberts, 1999).