Judge Herron was elected to the bench in November, 1987 and re-elected to a second ten year term in November, 1997. He has held various assignments in the Criminal Section and subsequently in the Civil Section of the Trial Division and has served on numerous judicial committees including serving as Chair of the Judicial Accountability Committee and the Civil Management Committee.

From January, 1996 to February, 2002, Judge Herron was appointed by the Supreme Court of Pennsylvania as the Administrative Judge of the Trial Division and supervised 70 judges assigned to the Civil and Criminal Programs, as well as approximately 1,000 Court employees in this largest of three divisions of the Court. He worked to modernize and streamline the civil complaint, motion and discovery filing processes, initiated a Commercial Law Civil Trial Program and organized the Court into judicial teams, a greatly improved method for achieving significant dispositions of cases. Among the many accomplishments under his tenure were the reduction of the civil major jury backlog from 13,000 cases to 6, 500; implementation of a Jury Scofflaw Court and improved community acceptance of jury service; relocation of the 600 member Probation and Pretrial Divisions to a new functionally designed building and reorganization of the Department for enhanced parole and probation services; and settlement of a 30 year old prison litigation case (Jackson v. Hendrick). His administration was widely lauded for innovations that improved both the efficiency of the court and the treatment of those who come before it.

The Commerce Program created by Judge Herron was then and remains today the only such program in Pennsylvania and has been universally hailed and recognized for its excellence. Judge Herron, even while serving as the Administrative Judge, served as one of the two judges in this program and authored over 150 opinions while performing the assignment.

Prior to judicial service, Judge Herron was an associate in a Philadelphia law firm (1969-1971); an Assistant District Attorney (1971-1972) under (now Senator) Arlen Spector; Disciplinary Counsel for the Supreme Court of Pennsylvania's Disciplinary Board and eventually serving as Chief Disciplinary Counsel (1973-1985); and Deputy District Attorney for investigations (1986-1987) under (now Chief Justice) Ronald Castille.

During his judicial service, Judge Herron has appeared frequently as a lecturer and panelist in various continuing legal education programs and has taught law school courses in both Professional Responsibility and Trial Advocacy. From 1993 to 1996, he served as a gubernatorial appointee to the constitutionally created Judicial Conduct Board. He has held memberships in the Temple Inn of Court and the University of Pennsylvania Law School Inn of Court and is a member of the Junior Legal Club.

He has received numerous awards including the American Legion Service Award (1999), the Philadelphia Bar Association Person of the Year (1998) and received the Pennsylvania Bar Association's highest rating in 2003 as a candidate for election to the Pennsylvania Supreme Court.

The Supreme Court of Pennsylvania appointed the Hon. John W. Herron as administrative judge of the Trial Division of the Court of Common Pleas of the First Judicial District (FJD) on November 10, 2011.

Judge Herron received a B.A. from Duke University in 1966 and a J.D. from Dickinson Law School in 1969.