Mariah F. DiGrino

Steve is a partner in the firm’s Litigation Department, where he represents clients in complex civil litigation matters before state and federal courts throughout the country. He has considerable experience with commercial disputes, constitutional challenges, statutory interpretation issues, and defamation and invasion of privacy suits. He is skilled at representing municipalities in cases involving so-called “locally undesirable land uses” such as airports, music amphitheat...

John Augustyn is a top attorney recognized by Best Lawyers in the practice area(s) of Litigation - Intellectual Property and Patent Law. John, who practices law in Chicago, Illinois, has been recognized since 2019. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which John is held by other top lawyers in the same geographic and legal practice area.

Chris P. Kallos is a top attorney recognized by Best Lawyers in the practice area(s) of Private Funds / Hedge Funds Law. Chris P., who practices law in Chicago, Illinois, has been recognized since 2026. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Chris P. is held by other top lawyers in the same geographic and legal practice area.

Margaret H. (“Peggy”) MCCORMICK is a principal of Minsky, McCormick & Hallagan, P.C., and has been practicing exclusively in the field of immigration law for over thirty years. From 1999 until 2003, she served as national President of the American Immigration Law Foundation, and during her tenure, she established the Immigration Policy Center to increase public understanding of immigration. She is past national President of the American Immigration Lawyers Association (1997-98). She curre...

As a partner in the Intellectual Property practice group, Jeff focuses his work on patent litigation and strategic counseling related to pharmaceutical, chemical, biotechnology, electrical engineering, agricultural and food products. A registered patent attorney with four decades of experience, Jeff has successfully represented both patent owners and patent challengers through all stages of federal litigation and appeals. A significant portion of Jeff’s practice includes advising pharma...

Daniel S. Kirschner is a partner at the Chicago plaintiffs’ law firm of Corboy & Demetrio. As a trial lawyer, Mr. Kirschner represents victims of catastrophic personal injury, wrongful death and medical malpractice. Mr, Kirschner has successfully handled cases against many of the nation’s largest insurance companies and corporations at the pretrial, trial and appellate levels in state and federal court in Illinois and throughout the United States.Mr. Kirschner concentrates his...

In each year since 2015, Bryan has been listed in the IAM Patent 1000 – The World’s Leading Patent Professionals for Litigation. He is also recognized in Patent Litigation: Full Coverage in the 2018, 2021 and 2022 editions of The Legal 500 United States. Bryan has litigated and counseled on patent matters for companies of various sizes across a variety of complex industries and technologies including medical devices, optical networking, pharmaceuticals, 3-D technology, material co...

Richard Sirus is a top attorney recognized by Best Lawyers in the practice area(s) of Employee Benefits (ERISA) Law. Richard, who practices law in Chicago, Illinois, has been recognized since 2025. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Richard is held by other top lawyers in the same geographic and legal practice area.

Mark Grossmann is global chair of Katten's Corporate practice. Mark knows how to make deals happen. For more than 20 years, he has guided principals and finance sources alike through critical transactions that have helped them grow, compete and realize value. He is known for a refreshingly direct approach that cuts away extraneous issues and gets to the heart of what the parties need. Mark knows that lawyers are often seen as obstacles who can bury the deal in the legal details. He takes a di...

Sanford E. Perl (Sandy) concentrates on the corporate, securities and tax aspects of complex business transactions, including leveraged buy-outs of public and private companies; strategic mergers, acquisitions, investments and joint ventures; venture capital and growth equity investments; divestitures; initial public offerings; private equity fund formations; executive compensation; and debt and equity restructurings and workouts. He manages transactions in a wide variety of industries, inclu...