Sean O'Brien
Sean O'Brien
Senior Counsel
He/Him/His
"With nearly two decades of experience as a prosecutor and defense attorney, I give clients an insider’s view of how government agencies investigate, decide, and act."
Sean O'Brien
Senior Counsel
He/Him/His
"With nearly two decades of experience as a prosecutor and defense attorney, I give clients an insider’s view of how government agencies investigate, decide, and act."
About Sean
Sean brings an individual perspective to government and regulatory matters, having built cases as a Cook County prosecutor and later defended clients in both criminal and regulatory proceedings. That combined experience gives him a genuine insider’s view of how government agencies investigate, evaluate evidence, and decide whether to act. These are insights his clients rely on when navigating regulatory scrutiny, compliance questions, or an active government inquiry.
Sean’s approach is practical rather than reactive. He helps clients understand what an agency is actually looking for, where their exposure lies, and how to respond in a way that protects their interests without unnecessarily escalating the matter.
Areas of Focus
Industries:
Services:
Experience
- Secured a not guilty verdict on an attempted murder charge in Cook County.
- Successfully litigated a case of first impression in Cook County state court challenging the judicial authorization of a confidential overhear on Fourth Amendment grounds.
- Won all 12 felony jury trials litigated as both a prosecutor and defense attorney.
Recognition
- University of Illinois Chicago School of Law, Trial Advocacy and Dispute Resolution Honors Board, Vice Barrister and Chief Barrister; Chicago Inn of Court
Credentials
Education
- University of Illinois Chicago School of Law, JD, with honors
- University of Wisconsin – Whitewater, BA
Bar Admissions
- Illinois
Thought Leadership
Presentations
Sean is an annual guest speaker for "Criminal Justice in the City" at DePaul University College of Law.
Interests
Sean’s primary interest is spending as much time with his family as possible before his sons head off to college. He’s passionate about classic cinema, music, and sports. On weekends, he can often be found tending a fire in his BBQ pit.
Community/Civic Activities
- Village of Riverside, Parks & Recreation Board, 2018 – 2024
Thought Leadership
Presentations
Sean is an annual guest speaker for "Criminal Justice in the City" at DePaul University College of Law.
