Armstrong Teasdale announced the addition of Litigation Partner Michael K. Mullen to the firm’s St. Louis office. A former circuit judge in the Missouri 22nd Judicial Circuit Court, he focuses his practice on arbitration, mediation, special master work and general trial work. He joins a roster of more than 750 lawyers and staff professionals across Armstrong Teasdale’s 17 offices internationally.
Mullen has more than three decades of diverse legal experience including roles on the bench, in private practice, and as an assistant circuit attorney for the City of St. Louis. As a 22nd Judicial Circuit Court judge, he presided over a number of high-profile, multi-week and multimillion-dollar trials.
Mullen brings his in-depth insight into the workings of the court to his client representations, having tried multiple cases and presided over countless others, both bench and jury trials, involving felonies as well as high-value civil disputes.
During his time on the court, Mullen established St. Louis’ Criminal Justice Coordinating Council, comprised of intergovernmental agency leaders working to enhance public safety through coordinated decision-making; and the city’s felony redirect program, allowing people with low-level felonies to enter alternative rehabilitation programs.
Mullen served as circuit court judge on the Missouri 22nd Judicial Circuit Court from 2008 to 2023. He presided over the mass tort docket for the City of St. Louis and, from 2017-2018, he served as presiding judge over the 22nd Circuit. He joined the court as an associate circuit judge in 2001.
Before that, Mullen was in private practice at several St. Louis area law firms, and previously worked as an assistant circuit attorney with the St. Louis Circuit Attorney’s Office. He has also taught criminal law as an adjunct professor at the University of Missouri-St. Louis.
Armstrong Teasdale is a partner-owned law firm headquartered in St. Louis.

























