Peter maintains a trial and appellate practice in criminal law and related matters. He regularly appears before every level of court in Ontario. Peter handles all types of criminal cases, from common assault and drinking and driving to homicide matters. He has a particular interest in cases involving complex legal issues or expert scientific or technical evidence in areas including accident reconstruction, medical causation, and computer forensics.

In addition to his criminal law practice, Peter represents lawyers and paralegals in relation to complaints and discipline matters before the Law Society of Upper Canada. Peter acts for licenced establishments in Alcohol and Gaming Commission matters before the Licence Appeal Tribunal, as well as in quasi-criminal prosecutions. Further, he appears on behalf of individuals in hearings before the Ontario Review Board and in appeals from dispositions imposed by the Board.

Peter is a member of Legal Aid Ontario's Complex Case and Extremely Serious Matters panels. He accepts legal aid in relation to serious cases at the trial and appellate level, as well as in mental health matters. As a member of the Pro Bono Inmate Appeal Program, he appears before the Court of Appeal for Ontario and argues appeals on behalf of unrepresented indigent individuals.

Peter has lectured and presented papers at continuing legal education programs and conferences held by various organizations including the Criminal Lawyers’ Association, Osgoode Professional DeveloPMent, the Advocates’ Society, the Law Society of Upper Canada and the Ontario Bar Association.