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Mark Halfyard.
Senior appellate lawyer. Appeal counsel at the Court of Appeal for Ontario and the Supreme Court of Canada.
Mark C. Halfyard is the senior appellate lawyer at Daniel Brown Law, with over 20 years of experience in criminal appeals. He was called to the Ontario Bar in 2005.
Background and Certification
Mark obtained his B.A. in legal studies and political science from Carleton University (2001), graduating top of his faculty. He graduated with honours from the University of Ottawa Faculty of Law (2004), and completed a clerkship with the Regional Senior Judge of the Ontario Superior Court.
The Law Society of Ontario has certified Mark as a specialist in criminal law — a designation held by fewer than 2% of criminal lawyers in the province, recognizing both experience and adherence to high standards of professional practice. He has also been recognized by Best Lawyers in Canada for Appellate Litigation and Criminal Defence, and named by Post City Magazine as one of Toronto's Top Appellate Lawyers.
In 2024, Mark was inducted as a Fellow of the Litigation Counsel of America, an invitation-only, peer-selected honorary society of 3,500 trial lawyers across North America — representing fewer than one in 200 of all practising lawyers. He is a member of the Litigation Counsel of America’s Trial Law Institute and Diversity Law Institute.
From Mark’s bio
A criminal conviction does not have to be the end of the road.
Appellate Practice
Mark is one of Canada’s most prolific appellate lawyers, having argued over 400 appeals at the Court of Appeal for Ontario. He also appears regularly as appellate counsel in the Superior Court of Justice and the Federal courts.
He has overturned convictions for offences including murder, sexual assault, drug trafficking and importing, impaired driving, robbery, fraud, firearms, kidnapping, and child abduction.
Supreme Court of Canada
Mark has appeared more than ten times as appellate counsel at the Supreme Court of Canada. He has argued leading cases there on the expertise of drug recognition experts (DREs), sexual assault, the right to trial within a reasonable time, mandatory minimum sentences, the constitutionality of the sexual offender registry (SOIRA), improper Crown practices in jury selection, and the presumption of innocence.
He has a particular interest in cases involving racial bias and Charter violations, and is a strong advocate for procedural fairness in the criminal justice system. Mark has also advocated for in-custody clients’ right to adequate food, the right to full and fair Crown disclosure, and against false confessions.
Writing and Teaching
Mark is the co-author of Criminal Appeals (Emond Publishing). He has published articles on criminal law and appellate practice, and is regularly consulted by the media for commentary on appellate issues — see the firm’s media coverage.
He is an adjunct professor at Osgoode Hall Law School (Criminal Law LL.M. Program) and the University of Toronto Faculty of Law (Appellate Externship Program). He has taught criminal law at Ontario Tech University with a focus on organized crime, and has taught courses on constitutional law, evidence, and oral advocacy. Mark regularly appears as a guest lecturer at legal conferences for defence lawyers, Crown counsel, and judicial continuing education programs.
Leadership and Pro Bono Work
Mark is a Toronto Director of the Criminal Lawyers’ Association (CLA), where he co-Chairs the Litigation Committee, which oversees interventions at the Supreme Court of Canada. He also Chairs the Pro Bono Inmate Appeal Program (PIAP), which assists unrepresented appellants before the Court of Appeal for Ontario, and has volunteered as review counsel for Innocence Canada.
Notable appeals
Mark Halfyard has argued hundreds of appeals at the Court of Appeal for Ontario and has appeared more than ten times before the Supreme Court of Canada. The decisions below are a selection of his reported appellate work, organized by area; each links to the full ruling on CanLII. Most appellate wins result in a conviction being overturned and a new trial ordered, or a Charter remedy, with outright acquittals noted where they were entered.
Supreme Court of Canada6
Evidence of a complainant’s sexual inactivity is “sexual history” under s. 276 and presumptively inadmissible. Intervener, Criminal Lawyers’ Association.
Mandatory and lifetime sex-offender registration (SOIRA) struck down as overbroad under s. 7. Intervener, Criminal Lawyers’ Association.
Condom use and the scope of consent to “the sexual activity in question” under s. 273.1. Intervener, Criminal Lawyers’ Association.
Landmark child-luring ruling; the s. 172.1(3) presumption of belief in age struck down as unconstitutional. Counsel for the accused.
Admissibility of Drug Recognition Expert evidence in the impaired-driving regime. Intervener, Criminal Lawyers’ Association.
Leading authority on the right to be tried within a reasonable time (s. 11(b)); delay found unreasonable and the stay of proceedings restored. Counsel for the accused.
Sexual offences25
Trial judge’s prolonged questioning of the accused amounted to cross-examination and raised a reasonable apprehension of bias; sexual assault conviction quashed, new trial ordered.
Conviction overturned for a material misapprehension of the evidence.
Improper restriction of cross-examination; convictions quashed, new trial ordered.
Conviction quashed and new trial ordered.
Post-conviction sentencing delay breached s. 11(b); sentence reduced as a Charter remedy.
Misapplied Browne v. Dunn rule in the jury charge; conviction quashed, new trial ordered.
Jordan delay exceeded the ceiling; stay of proceedings entered.
Jury wrongly permitted to convict on a negligence standard; conviction set aside, new trial ordered.
Historical child sexual-offence convictions set aside; new trial ordered.
Misdirection on fabricated statements as evidence of guilt; convictions set aside, new trial ordered.
Sentence found unfit and reduced from 10 to 8 years.
Misapprehension of the complainant’s evidence; convictions set aside, new trial ordered.
Failure to consider whether the complainant’s evidence raised a reasonable doubt; conviction set aside, new trial ordered.
Released on bail pending the conviction appeal, including recognition of an out-of-province surety.
Improper reliance on personal experience and outside material; conviction set aside, new trial ordered.
Improper admission of prior discreditable-conduct evidence; new trial ordered.
Trial judge relied on stereotypes rather than evidence; conviction set aside, new trial ordered.
Error in the W.(D.) credibility analysis; new trial ordered.
Sexual-interference conviction set aside; new trial ordered.
Conviction set aside where the trial judge reasoned from academic literature rather than the evidence; the Crown did not retry.
No reasons for refusing to sever counts; convictions set aside, new trial ordered.
Granted bail pending appeal following an eight-year sentence.
Reasonable apprehension of bias from the trial judge’s conduct; conviction set aside, new trial ordered.
Conviction set aside; new trial ordered.
Crown sentence appeal dismissed; the favourable sentence upheld.
Child exploitation5
Misapprehension of the evidence on knowledge; convictions set aside, new trial ordered.
Child-luring convictions set aside in light of Morrison; new trial ordered.
Child-pornography convictions quashed; new trial ordered.
One-year mandatory minimum for child luring struck down; Crown sentence appeal dismissed.
Crown appeal from acquittal dismissed; acquittal upheld.
Drug offences13
Sentence reduced after the court rejected an unproven “high-level trafficker” characterization.
Reasonable apprehension of bias; trafficking conviction set aside, new trial ordered.
Improper ultimate-issue opinion; trafficking conviction reduced to simple possession with an absolute discharge.
Deficient jury charge; convictions quashed, new trial ordered.
Inadmissible anecdotal expert evidence on importing; new trial ordered.
Leading racial-profiling decision; convictions set aside, new trial ordered.
Lawfulness of the arrest not properly determined; conviction set aside, new trial ordered.
Charter breach; evidence excluded and acquittals entered on all counts.
Fentanyl-trafficking sentence reduced from 33 to 20 months. Appeared as amicus curiae.
Trafficking sentence reduced from eight to five years.
Circumstantial possession case; conviction quashed and acquittal entered.
Conditional discharge substituted for a conviction and fine.
Crown sentence appeal dismissed; conditional sentence upheld.
Homicide5
Reasonable apprehension of bias from judicial pressure to plead; second-degree murder conviction set aside, new trial ordered.
First-degree murder conviction set aside on jury-charge errors; new trial ordered.
Provocation should have gone to the jury; second-degree murder conviction set aside, new trial ordered.
Second-degree murder conviction set aside; new trial ordered.
Accessory-after-the-fact-to-murder conviction set aside and acquittal entered.
Firearms and weapons3
Firearms convictions overturned on a misapprehension of evidence; co-accused acquitted and the client granted a new trial.
Right to counsel breached; drug and firearm evidence excluded and acquittals on all counts.
Landmark ruling striking the three-year mandatory minimum for a loaded prohibited firearm (s. 95); on re-sentencing, no further custody imposed.
Robbery, assault and violence9
Confused jury instructions on party liability; home-invasion convictions quashed, new trial ordered.
Assault conviction set aside; new trial ordered.
Misapprehension of the evidence on self-defence; new trial ordered.
Inadequate caution on eyewitness identification; aggravated-assault conviction set aside, new trial ordered.
Conditional discharge substituted after the more serious conviction was set aside.
Aggravated-assault convictions set aside; new trial ordered.
Youth’s videotaped statement wrongly admitted; robbery convictions set aside, new trial ordered.
Aggravated-assault convictions set aside; new trial ordered.
Fresh evidence admitted; assault conviction set aside, new trial ordered.
Impaired and dangerous driving6
Crown appeal from a dangerous-driving acquittal dismissed; acquittal stands.
Right-to-counsel issue unresolved at trial; conviction overturned, new trial ordered.
Crown/police appeal dismissed; defence disclosure of the Drug Recognition Expert’s records upheld.
Crown appeal from an acquittal on dangerous driving causing bodily harm dismissed.
Misapprehension of evidence on an alternative drinking scenario; conviction quashed, new trial ordered.
Crown sentence appeal dismissed; sentence upheld.
Charter, evidence and procedure6
Conviction for assault causing bodily harm quashed; new trial ordered on that count.
Accused who elected and requested a preliminary inquiry before the Bill C-75 amendments retained that right.
Fresh toxicology evidence admitted; conviction set aside, new trial ordered.
Crown appeal from an acquittal dismissed; acquittal upheld.
Order committing the accused for trial quashed; the preliminary-inquiry discharge reinstated.
Cumulative evidentiary errors; conviction set aside, new trial ordered.
Sentence appeals8
Sentence reduced. Appeared as duty counsel.
Fresh evidence of exceptional pre-sentence custody; sentence reduced to time served.
Suspended sentence replaced with a conditional discharge.
Crown sentence appeal dismissed; broad approach to pre-sentence custody credit upheld.
Criminal-harassment sentence reduced.
Custodial sentence replaced with a conditional sentence.
Sentence reduced after the trial judge departed from a joint submission.
Restitution order reduced on fresh evidence.
Credentials
- Courts
- Supreme Court of Canada; Court of Appeal for Ontario; Superior Court of Justice; Federal courts
- Education
- Carleton University, B.A. in legal studies and political science; University of Ottawa, Faculty of Law
- Clerkship
- Regional Senior Judge, Ontario Superior Court
- Certification
- Certified specialist in criminal law, Law Society of Ontario
- Memberships
- Fellow, Litigation Counsel of America; Toronto Director, Criminal Lawyers’ Association
- Pro bono
- Chair, Pro Bono Inmate Appeal Program; review counsel, Innocence Canada
Writing and teaching
- Co-author, Criminal Appeals (Emond Publishing)
- Adjunct professor, Osgoode Hall Law School (Criminal Law LL.M. Program)
- Adjunct professor, University of Toronto Faculty of Law (Appellate Externship Program)
- Ontario Tech University
- Guest lecturer for defence lawyers, Crown counsel and judicial continuing education
Mark defends every kind of criminal charge
Here are some of the charges we defend most often. We also defend charges not listed here.
The strength of the whole firm, on every case
Mark is one of 16 criminal defence lawyers at Daniel Brown Law. Every client has the firm’s collective trial and appeal experience behind them, in courthouses across Ontario.
Crime, Nationwide
Chambers Canada, 2027
Best Law Firms: Criminal Law
The Globe and Mail, 2026
Top Criminal Law Boutique
Canadian Lawyer, 2026–27
Criminal Defence, Tier 1
Best Law Firms Canada, 2026
Best Lawyers in Canada
Criminal Defence, 2027
Toronto Star Readers’ Choice
Best Law Firm and Best Legal Services, repeat winner
Talk to Mark about your appeal
Consultations are confidential. A criminal conviction does not have to be the end of the road. Mark can be reached by email at [email protected] or by phone at (416) 297-7200 x102.