Marvin Katz, senior judge of U.S. District Court here

Marvin Katz, 79, of Center City, a senior judge of U.S. District Court for the Eastern District of Pennsylvania, died Tuesday, Oct. 12, of complications from Parkinson's disease at home.

Appointed to the federal bench in 1983, Judge Katz became a senior judge in 1997 and continued to hear cases until becoming ill in April 2008.

"Judge Katz was extremely intelligent and knew the law. He wrote concise, to-the-point opinions that were marked with clarity," said Judge Harvey Bartle III, chief judge for the Eastern District. "He ran an efficient courtroom but was courteous and never intimidated people."

Judge Katz presided over several important criminal and civil cases, including a landmark patent case.

In 1996, the U.S. Supreme Court affirmed his decision in Markman v. Westview Instruments that judges, not juries, would evaluate and decide the meaning of the words used in patent claims.

In the 1980s, Judge Katz's ruling that the Department of Transportation could not put an arbitrary cap on public funding for handicapped-accessible buses and paratransit resulted in enhanced spending to accommodate the handicapped and the elderly.

Also in the 1980s, Judge Katz presided over the notorious "Roofers case." Stephen Traitz Jr., former head of the roofers' union, and his sons, son-in-law, and nine other former union leaders were convicted in November 1987 of taking part in a scheme to bribe Philadelphia judges and other public officials, collect debts for the mob, and inflict violence on contractors who failed to make extortion payments to the union.

Judge Katz grew up in Kensington and Germantown, and graduated from Central High School. He earned a bachelor's degree from the University of Pennsylvania, where he was Phi Beta Kappa. After graduating from Yale University Law School in 1954, he established a practice with a classmate, Arlen Specter, now a U.S. senator.

In a statement issued Tuesday, Specter said, "Judge Katz was an extraordinary lawyer and great jurist. We were best friends since college, debated Oxford University together, attended law school together, and were later partners. I never knew a lawyer who matched his analytical skills and brilliance."

Besides his law practice, Judge Katz was a law clerk to a Common Pleas Court judge for a year and was assistant to the commissioner of the IRS from 1977 to 1981.

He loved his work, his son Robert said, and enjoyed reading and vacations at the Jersey Shore.

In addition to his son, Judge Katz is survived by a brother and three nieces. He was predeceased by his former wife, Relli Eisenberg Katz.

A service and burial are private.

Memorial donations may be made to the National Parkinson Foundation, 330 S. Ninth St. , Philadelphia 19107.