About Us

Who We Are

Centurion Group DC, LLC (Centurion) was founded to offer clients a better solution for government relations regulatory compliance management. After spending years honing his expertise in compliance and business management, Centurion founder Patrick Callahan realized there must be a better way to help businesses navigate the niche world of political activities compliance. In 2011, Patrick formed Centurion in order to provide all industries with the kind of broad experience and precise knowledge that a dedicated, outsourced organization can deliver.

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Click here for a one-page information sheet.

Our Mission

Provide adaptive compliance and control risk management solutions that enable clients to focus on business objectives while addressing the challenging climate of global political and government relations compliance. Simply put: we promote a culture of compliance in your business while saving you time and money.

Meet the Leadership Team

Patrick M. Callahan


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Mr. Callahan’s expertise with political activities compliance matters includes, but is not limited to, legislative and procurement lobbying disclosures, pay-to-play, campaign contributions and finance, gift tracking and disclosure, foreign agent registrations, and political action committee and fundraising communications compliance. Mr. Callahan has been described as, “the person you want in a high pressure demanding environment. He is absolutely in charge–nothing gets overlooked and he is anticipating the next ten things before anyone else has thought about them. ” -Serena Moe, Former Managing Director, General Counsel, Global Sanctions Compliance, Citigroup. 

With more than 25 years of professional hands-on business management and compliance experience, Mr. Callahan offers Centurion Group DC, LLC clients the necessary expertise in dealing with regulatory disclosures matters. He also brings to the business an expertise in risk management, operations and project management, continuity planning, information security, financial planning and analysis, governance, event planning, auditing, and policy management. Mr. Callahan is a member of the Society of Corporate Compliance and Ethics.

A native of Florida, where he studied Business Management at Jacksonville University, Callahan currently resides in the Logan Circle neighborhood of Washington, DC where his love of animals includes his feisty Brussel Griffin and a Black Labrador.  He is an active member of Luther Place Memorial Church, and serves on the Church Council Leadership Team.

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Shannon E. Patrick



As Vice President of Centurion, Shannon manages the team with a focus on business development, strategic planning, organization operations, and client relations. Since starting as Associate with the firm in 2014, she has completed the Leadership Professional in Ethics & Compliance through the Ethics & Compliance Initiative, and looks forward to sitting for the LPEC exam. Shannon also contributes to Centurion’s regular publications in “Compliance & Ethics Professional, A Publication of the Society of Corporate Compliance and Ethics.”

Since assuming the role of Vice President at Centurion, Shannon has focused largely on brand and business development. Collaborating with the team to nearly double the size of the portfolio in the last two years, she is focused on managing corporate and trade association clients in the financial services industry.

An active member of the professional community in Washington, DC, Shannon Co-Founded the Government Affairs Industry Network and currently serves and Vice Chair of the Advisory Board, is a Member of the Organizing Committee of the Congressional Women’s Softball Game, a Leadership Member of Women in Government Relations as a Co-Chair of the Financial Services Task Force, a Mentor for the Public Leadership Education Network, sits on the Advisory Board of the Grassroots Professional Network, and is a Member of the Society of Corporate Compliance & Ethics. Shannon joins Centurion with prior experience in association government affairs, social media marketing and brand discoverability, research, and writing.

A native of Baltimore, Maryland, Shannon attended the University of Maryland, College Park where she studied English Language & Literature. In her spare time she enjoys seeing live music, cooking, paddle boarding, and doting on her dog.

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