Before his appointment to the bench, Justice David S. Rose was a criminal defence lawyer in Toronto, Ontario. He was called to the bar of Ontario in 2001 by the Law Society of Upper Canada (now the Law Society of Ontario).
Rose practised criminal defence as a named partner at Neuberger Rose LLP, a prominent Toronto criminal defence firm located at 1392 Eglinton Avenue West. The firm, which he co-led with Joseph A. Neuberger, was established circa 1998 and built a reputation as one of Canada's high-profile criminal defence practices. The firm handled a wide range of serious criminal matters, including sexual assault, domestic assault, impaired driving, drug offences, fraud, homicide, and Charter-related cases. The firm also served clients across the Greater Toronto Area, including Markham, Newmarket, North York, Richmond Hill, Thornhill, and Vaughan.
Rose and Neuberger jointly authored a legal publication called "Charter Alert," a newsletter highlighting recent court judgments dealing with issues arising under the Canadian Charter of Rights and Freedoms. This publication demonstrated Rose's expertise in constitutional and Charter-based criminal defence.