Criminal defence wasn’t a career move for Sean Fagan — it was the environment he was raised in. His upbringing reads like a blueprint for producing a top criminal defence lawyer.

The son of one of Calgary’s most respected criminal defence lawyers, his earliest exposure to the justice system came not in law school — but as a child, spending weekends and evenings in a criminal law office. Without realizing it, he was being trained. Years before he entered a courtroom, he was absorbing the language, strategy, and mindset required to become a top defence lawyer. By the time he enrolled in law school, the path was clear.

At law school, he focused exclusively on criminal law. He directed all of his energy into trial work and defence strategy. He committed early — and it showed. Sean won the Faculty of Law Trial Advocacy Championship, then took first place at the MacIntyre Cup (Western Canada’s premier trial advocacy competition), and went on to medal at the Sopinka Cup, Canada’s national trial advocacy finals. From the outset, his focus was singular: win.

He has never deviated from that focus. From the first day of practice, Sean has worked only as a criminal defence lawyer — no family law, no civil litigation, no administrative work. Just criminal law. In a profession where many lawyers divide their attention across multiple practice areas, Sean made the deliberate choice to go narrow and deep, not wide. Criminal law is complex and unforgiving. Results requires full commitment.

Over the years, he has built a reputation for defending serious charges and delivering results in difficult, high-stakes cases. His clients have included individuals charged with assault, drug trafficking, firearms offences, and murder — and he has appeared in courtrooms across Canada, from British Columbia to Newfoundland.

Sean was lead defence counsel in one of the most important criminal law cases in Canadian history. In a landmark ruling at the Supreme Court of Canada, he secured a full acquittal and was successful in having a 30-year-old criminal law struck down. The decision re-established the defence of extreme intoxication and now stands as a foundational precedent in Canadian criminal law.

He continues to maintain a low-volume, highly selective practice, representing clients on a case-by-case basis. He does not accept legal aid, and he does not take on every file that comes through the door. This structure allows for the kind of detailed, strategic attention that serious criminal defence in Calgary demands.

Sean Fagan is not inexpensive. But getting the hours, focus, and attention of a highly skilled lawyer is never cheap. Criminal defence is not something to cut corners on. Choosing a lawyer you’re not confident in will leave you second-guessing key decisions and questioning the direction of your case when it matters most. Switching counsel partway through can gut potential procedural defences — and sometimes, the damage has already been done. You do not want to wait to hire the best lawyer you can afford until it’s too late. The odds of winning are substantially higher at trial than on appeal.