Judge Robert A. Hendrickson was elected to the Twelfth District Court of Appeals on November 4, 2008, replacing the retired Honorable James E. Walsh. Before beginning his first term on February 9, 2009, Judge Hendrickson served as Butler County Area III Court Judge, West Chester, Ohio from 1997 to 2008. He is past President of the Butler County Municipal and County Court Association and past Administrative Judge of the Butler County Area Courts. He also served as a City Councilman in Monroe, Ohio in 1996; as a Magistrate for the Hamilton Municipal Court in 1996; as an acting prosecutor for both Hamilton and Middletown Municipal Courts; as an acting warrant officer for Hamilton Municipal Court; as a public defender in the Butler County courts from 1985 to 1996; and as an attorney in private practice for over 23 years in Monroe.

Judge Hendrickson has been a member of the Ohio Municipal and County Court Judges Association, Ohio Bar Association, Butler County Bar Association, and Warren County Bar Association.

Judge Hendrickson was born in Middletown, Ohio on January 8, 1959, and raised in Monroe, Ohio. He was the youngest of four children born to retired 12th District Court of Appeals Judge William R. Hendrickson and Gloria Hendrickson. Judge Hendrickson graduated from Monroe High School in 1977. He continued his education and graduated from the University of Cincinnati with a Bachelor's Degree in Business Administration in 1981 and from the Capital University Law School in 1984. Judge Hendrickson was Vice President of his law school class and President of the Honor Code.

Judge Hendrickson is married to Deb and they reside in Monroe, Ohio with their family, Robby, Cassie, Danielle and grandson Ethan.

Judge Hendrickson's civic involvement includes Board of Directors member/past President-Sonlight Power, Inc. (a mission organization that installs solar panel systems in third world countries for churches, schools, medical facilities, and orphanages); Treasurer/Board of Director's member-Monroe Area Community Foundation; and a Kentucky Colonel. Judge Hendrickson is past President of the Monroe Lions Club, past President of the Monroe Chamber of Commerce, past President of the Monroe Sports Association (baseball league), past President of the Monroe Youth Basketball League, and past Vice-President of the Butler County Law Library Association.

Judge Robin N. Piper began serving on the Twelfth District Court of Appeals on February 8, 2011. Judge Piper had previously been the elected prosecutor for Butler County for over ten years. Prior to being elected prosecutor, Judge Piper was an assistant prosecutor for nearly 14 years and personally handled multiple high profile felony cases.

Judge Piper has presented oral argument before the Ohio Supreme Court on both civil and criminal cases. He served as a Special Prosecutor on several occasions, most notably the Lucasville Prison Riot prosecutions. Judge Piper has been a guest speaker before the Ohio State Coroners Association on Tissue Procurement in Child Abuse Cases, before the Ohio Municipal Court Judges Association on the Prosecution's View, and before numerous student groups on such subjects as Shaken Baby, the Death Penalty, and Teen Responsibility.

Judge Piper participated in numerous programs designed to educate and minimize risk among our youth. Such programs included DARE, GREAT, Character Week, After Prom Safety and Awareness, and an annual Student Council Summit at Miami University Middletown.

Judge Piper also was the sole proprietor of Piper Law Offices, a private general practice involving legal matters and litigation in all areas of the law. During his career, Judge Piper has served as an acting municipal prosecutor, acting judge in Area Courts, and arbitrator for common pleas court. Prior to becoming a judge on the Court of Appeals, he participated on numerous boards for charitable organizations and was a member of several civic organizations.

Judge Piper graduated from Hamilton Taft Senior High School in Hamilton, Ohio, in 1971, Miami University, Oxford, in Public Administration, in 1978, and the University of Dayton School of Law, Juris Doctorate, in 1982.

As empty nesters, Judge Piper and his wife have a small log house in Hanover Township, Butler County, where they live with their three dogs.

Judge Michael E. Powell was appointed to the 12th District Court of Appeals by Governor John Kasich on October 4, 2012 and was subsequently elected on November 6, 2012. Prior to serving on the Court of Appeals, Judge Powell served as Warren County's Probate and Juvenile Court Judge from April 2000 to October 2012. Judge Powell worked as a Warren County assistant prosecuting attorney from December 1979 until April 2000. During his tenure at the Warren County Prosecutor's Office, Judge Powell worked as the Juvenile Court Prosecutor, the County Court Prosecutor and as a Common Pleas Court Prosecutor. Judge Powell has prosecuted cases as diverse as juvenile speeding cases to violent adult felonies, including rapes, robberies and homicides. From 1987 until 2000, Judge Powell served as the Chief Assistant Prosecutor and worked primarily in the civil division of the prosecutor's office, representing and advising the various county and township offices in Warren County.

Judge Powell maintained a private civil law practice from 1981 to 2000. Areas of practice included local government law, real estate and domestic relations. Judge Powell served as law director for Warren County's Hamilton Township and as village solicitor for the Village of Morrow, Ohio. Other clients included Butler County's Liberty and Lemon Townships, the Warren County Board of Realtors, the Landen Farms Community Services Association and various other homeowners' associations in southern Warren County.

Judge Powell has been involved in his community as Vice Chairman of the Warren County Salvation Army Advisory Board, Lebanon Kiwanis President, Chairman of Lebanon City School District bond issue campaigns in 1996 and 1997, member of the Ohio Supreme Court's Advisory Committee on Courthouse Security and Emergency Preparedness, member of the Countryside YMCA Human Resources Committee and as a youth soccer and basketball coach. Judge Powell is an inducted member of the Lebanon City Schools Hall of Fame and a recipient of the Earl J. Maag Award from the Warren County Republican Party in recognition of his service to the community and to local and county government.

Judge Powell received his B.A. in Political Science from Ohio Northern University in May 1976 and his J.D. from the Ohio Northern College of Law in 1979. Judge Powell was born and raised in Liberty Township in Butler County, Ohio and is a 1972 graduate of Lakota High School.

Judge Powell and his wife Suzanne reside in Clearcreek Township in Warren County, Ohio. They have two adult daughters.

Judge Matthew R. Byrne was elected to the Twelfth District Court of Appeals in 2020. Judge Byrne's term began on January 1, 2021.  He is currently serving as the court’s elected Administrative Judge.  Judge Byrne also currently serves as a member of the Ohio Supreme Court’s Commission on the Rules of Practice and Procedure (where he serves as chair of the Appellate Rules Committee) and the Board of Commissioners on Character and Fitness.

From January 2010 to December 2020, Judge Byrne practiced law at the national law firm of Jackson Lewis P.C. He was a member of the firm's General Employment Litigation Practice Group and the Wage and Hour Practice Group. From 2007 to 2010 he practiced at Taft Stettinius & Hollister LLP. At both firms, Judge Byrne represented clients ranging from small businesses to international corporations in state and federal trial and appellate litigation, including multiple class and collective actions. He also represented clients in arbitration and before numerous administrative agencies, including the Equal Employment Opportunity Commission, the National Labor Relations Board, and the Ohio Civil Rights Commission. Judge Byrne's litigation and administrative agency experience included matters in fourteen states.

Judge Byrne earned his law degree, cum laude, from The Ohio State University Moritz College of Law. During law school he was symposium editor of the Ohio State Law Journal and the winner of the Donald S. Teller Memorial Award for student writing contributing most significantly to the Ohio State Law Journal. During law school he clerked for the Acting General Counsel of the United States Department of the Treasury. Judge Byrne earned his bachelor's degree, magna cum laude, from Xavier University, where he majored in International Affairs (Business) and Political Science.

Prior to law school, Judge Byrne served as a member of the White House Staff in the Office of Presidential Personnel. In that role Judge Byrne was responsible for preparing documents submitted to President George W. Bush concerning his selection and nomination of appointees for high-level federal government positions, and for coordinating with the Offices of White House Counsel, Press Secretary, and Executive Clerk regarding candidate background clearances, press announcements, and the status of appointments/nominations.

Judge Byrne is active in a number of community and civic organizations. He has been a member of the Federalist Society since law school and he served for five years as the president of the Federalist Society's Cincinnati Lawyers Chapter. He is a member of the Ohio State Bar Association, the Butler County Bar Association, the Warren County Bar Association, and the Clermont County Bar Association. Judge Byrne previously was a member of the Advisory Board of Pregnancy Center East, and he is a board member and current board chair of the St. Thomas More Lawyers Guild of Greater Cincinnati.

Judge Byrne is an active parishioner at his church, where he is a lector, a member and former President of the Education Commission, and a former member of the Finance and Administration Commission. Judge Byrne resides in Deerfield Township, Warren County, with his wife Julie and their three children.