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Meet Hannah

Hannah Seigel Proff is a trial attorney who has represented hundreds of adults and juveniles in the state of Colorado over the last 10 years. Hannah is highly experienced in criminal and delinquency cases at all levels from misdemeanors to felonies. Before starting her private practice, Hannah practiced at Johnson & Klein, PLLC as a senior associate where she represented criminal and juvenile clients. Prior to Johnson & Klein, PLLC, Hannah was the policy director for the Colorado Juvenile Defender Center. In that role, she successfully lobbied for legislation in the Colorado General Assembly to improve the treatment of children and youth in the juvenile justice system in Colorado. Hannah was instrumental in getting landmark legislation passed that authorized resentencing hearings for individuals sentenced to life without parole for crimes committed when they were juveniles. Hannah previously spent seven years as a trial attorney in the Denver Office of the Colorado State Public Defender. During this time, she defended thousands of individuals and tried over 30 cases to verdict. As a result of her pretrial investigation and advocacy, Hannah has secured over 40 dismissals for clients before trial. 

Hannah’s defense experience and successful track record in the courtroom have led to invitations to lecture and share best practices at legal conferences and trainings across the country. With a genuine focus on collaboration, Hannah shares best practices in complex areas such as defending children charged as adults, and litigation techniques, and motions practice. 

Hannah is not only passionate in the courtroom but she is also committed to community, state, and national policy issues. In her spare time, Hannah invests her time volunteering, leading and consulting for several local organizations. Hannah serves as a consultant for private firms and the Colorado Juvenile Defender Center. Hannah is also an active member of the Denver-area legal community and a member of several bar associations. 

Hannah has received formal recognition and awards over her career including 5280 Magazine 2017, 2018 and 2019 “Top Lawyer” in juvenile defense.



University of San Francisco School of Law

J.D. and Public Interest Law Certificate, 2008 

University of Denver 

Bachelor of Arts, cum laude, 2004


Teaching Positions

  • Adjunct Professor, University of Denver Sturm College of Law

  • Faculty, University of Colorado School of Law Trial Advocacy

Authored Articles

Co-Author, “Evolving the Standard of Decency: How the Eighth Amendment Reduces the Prosecution of Children as Adults,” Colorado Lawyer (March 2018).


Author, “Justice Redirected:  The Impact of Reducing the Prosecution of Children as Adults in Colorado and the Continuing Need for Sentencing Reform,” (2015).


Memberships & Professional Associations

  • Colorado Bar Association

  • Denver Bar Association

  • Colorado Bar Association

    • Colorado Bar Association’s Leadership Training Program (COBALT)

  • Colorado Women’s Bar Association

  • Colorado Lesbian Gay Bisexual Transgender (LGBT) Bar Association

  • National Association of Criminal Defense Lawyers

  • Colorado Criminal Defense Bar Association


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