About Brian
Brian Sinclair has built a career that moves between public service and private practice. He has worked in county prosecutor’s offices and later opened his own firm. That mix of courtroom experience and solo practice shapes how he approaches cases.
Sinclair earned his J.D. from the University of Missouri–Columbia in 2000. Before law school he completed a B.A. at Washington University in St. Louis in 1999, studying history, political science and philosophy. Those studies framed an interest in public affairs and the rules that govern them.
He began his prosecutorial work in 2003 as a deputy prosecuting lawyer at the Boone County Prosecutor’s Office in Indiana. Two years later he moved to Missouri and served as an assistant prosecuting lawyer in the Lincoln County Prosecutor’s Office. Those years in county courts involved routine motions, jury trials and case management. They also exposed him to the variety of issues that can arise in criminal cases at the local level.
In 2010 Sinclair started Sinclair Law Office, LLC. He shifted from working for government offices to operating his own practice. Running a small firm required an expansion of skills beyond courtroom work. It meant handling client intake, file management and the business side of a law office, as well as advising clients on discrete legal questions.
Across his career he has been active in both Missouri and Indiana. He has worked under prosecutorial rules in county offices and now represents clients through his private practice. Colleagues describe him as practical in approach; he tends to favor direct legal analysis over flourish. His background gives him familiarity with trial procedure and local court processes in the two states where he is licensed.
As of 2026 he practices from Sinclair Law Office, LLC. His current practice focuses on representing clients in matters arising under the laws of Missouri and Indiana.
