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As a former corporate attorney for a Fortune 100 company with extensive litigation experience, Sonni is uniquely qualified to provide clients with practical, creative and sound legal advice compatible with today’s business environment.

She advises companies on general business strategy and commercial litigation and class action defense, as well as employment discrimination matters before the Equal Employment Opportunity Commission (EEOC), related state agencies and before state and federal courts. In addition, she represents employers regarding numerous regulatory issues, wage and hour laws, restrictive covenant agreements, reductions in force, and public policy discharge matters. In both trial and in alternative dispute resolutions, Sonni has achieved significant favorable outcomes.

Sonni’s experience also extends to representing employers in collective bargaining, arbitrations, union avoidance techniques, corporate campaigns, positive employee relations training and matters before the National Labor Relations Board.

Before joining the firm, Sonni was associate general counsel for Express Scripts Inc. in St. Louis. She was responsible for daily legal advice in all areas of labor and employment law, proactive strategy and training, compliance, litigation strategy, handling of EEOC matters, development of human resources policies and audit tools, budget management, selection, and oversight of outside law firms. Previously, she worked as employee relations counsel for Smurfit-Stone Container Corp. (now RockTenn) in St. Louis, where she provided litigation support and labor and employment counseling for 26 manufacturing facilities across the United States, including conducting all collective bargaining and defending EEOC matters.

Sonni is a member of the firm’s Executive Board.




  • The Best Lawyers in America®, Employment Law - Management, 2017-2024
  • Missouri Lawyers Weekly, Women's Justice Awards - Litigation Practitioner, 2019


  • J.D., Washington University in St. Louis School of Law
    • Washington University Law Quarterly, editor
  • B.A., University of Missouri


  • Missouri
  • U.S. District Court, Southern District of Illinois
  • Illinois
  • U.S. District Court, Eastern District of Missouri

Professional Memberships and Certifications

  • National Association of Manufacturers
  • Bar Association of Metropolitan St. Louis
  • Society for Human Resource Management
2023 Pro Bono Contributor
  • Favorable trial verdict in LLC withdrawal liability case with issues of first impression litigated.
  • In 2014, received a defense verdict in race discrimination jury trial for utility company in St. Louis City.
  • Obtained defense verdict in jury trial where plaintiff alleged discrimination and retaliation claims against her supervisor. Judge also awarded defendant $100,000 in attorneys’ fees.
  • Achieved favorable results in commercial trade secrets case against former employees who set up competing business.
  • Defeated multiple discrimination cases for Fortune 100 healthcare company by obtaining summary judgment.
  • Obtained favorable outcome for large pharmacy benefit management company in union corporate campaign where union sought to block the company from moving operations to different state.
  • Represented companies in concession bargaining with unions.
  • Defeated several union organizing efforts for union and nonunion companies.
  • Obtained summary judgment on alleged age and race discrimination claims with prejudice, including Section 1983 claim. Judge also awarded defendant over $25,000 in attorneys' fees.
Legal Updates | June 18, 2020
Workplace Issues and COVID-19