Martin J. Costello

John M. Hughes

Thomas R. Hughes

Katrina E. Joseph

John G. Dillon


Martin J. Costello


Martin J. Costello is a partner at Hughes & Costello, and specializes in criminal law and employment and labor law. Martin started his law career with the Ramsey County Attorney's Office; then worked with a Saint Paul law firm handling municipal clients; and, in 1992, co-founded the firm of Hughes & Costello. Martin has 29 years prosecution experience, working in various counties in the Twin Cities Area. He has tried hundreds of jury trials and court trials, and he has handled thousands of criminal, traffic, and ordinance violation cases. Martin now represents the Cities of Falcon Heights, Lauderdale, and Richfield.

Martin also handles arbitrations involving labor and employment law issues, representing Teamsters Local No. 120 in Saint Paul, Minnesota; Teamsters Joint Council 32 in Minneapolis, Minnesota; the Service Employees International Union Local 1; and the pre-merger Northwest Airlines Pilots' Red Book Merger Committee. Martin is also General Counsel to the International Brotherhood of Teamsters General Secretary-Treasurer, C. Thomas Keegel. During his career, Martin has arbitrated hundreds of labor grievances, and has represented unions in numerous labor cases in federal and state courts.

Bar Admissions
  • Minnesota state courts
  • Iowa state courts
  • New York state courts
  • Wisconsin state courts (pending)
  • U.S. Supreme Court
  • U.S. Court of Appeals for the Armed Forces
  • U.S. Court of Appeals for the District of Columbia
  • U.S. Court of Appeals for the Eighth Circuit
  • U.S. District Court for the District of Minnesota


Professional Associations
  • Member, Minnesota Supreme Court Advisory Committee on the Rules of Criminal Procedure
  • Member, Planning Committee for the Minnesota Criminal Justice Institute
  • Member, American Bar Association
  • Member, Minnesota State Bar Association
  • Member, Iowa State Bar Association
  • Member, Ramsey County Bar Association

  • Co-Author, Minnesota Misdemeanors and Moving Traffic Violations, 3rd Ed., Matthew Bender & Co., Inc. (1999 and subsequent supplements)
  • Co-Author, Minnesota Evidentiary Foundations, Michie Law Publishers (1996)
  • Contributing Editor, The Developing Labor Law, 4th and 5th Eds., BNA (2001, 2006)
  • Author, Hating the Sin, Loving the Sinner: The Minneapolis Children's Theatre Company Adolescent Sexual Abuse Prosecutions, Garland Publishing, Inc. (1991)

Teaching & Speaking Engagements
  • Instructor, Criminal Law and Procedure, William Mitchell College of Law
    (1975 – Present)
  • Adjunct Professor, Criminal Law and Procedure, University of Minnesota Law School (1974 – Present)
  • Faculty, Minnesota Criminal Justice Institute (1995 - Present)