Peter L. Zimroth, who for eight years as a court-appointed monitor oversaw a sharp decline in the New York City Police Department’s stop-and-frisk strategy without a consequent increase in crime, died on Sunday at his home in Manhattan. He was 78. The cause was pancreatic cancer, said his wife, Estelle Parsons, the Broadway and film actress. From 1990 to 2015, Mr. Zimroth was a partner with the law firm of Arnold & Porter, where he focused on products liability, commercial, securities, and white collar crime matters. Prior to joining the firm, Mr. Zimroth was Corporation Counsel of the City of New York. He was the architect of the City's law providing for the public financing of elections, a law which has become the model for local legislation around the country. Earlier in his career, Mr. Zimroth served as an Assistant U.S. Attorney for the Southern District of New York, Securities Fraud Unit, and as the Chief Assistant District Attorney in Manhattan. Mr. Zimroth was a tenured professor at the New York University School of Law and a law clerk to U.S. Supreme Court Justice Abe Fortas. Peter Lenard Zimroth was born on Jan. 11, 1943, in Brooklyn. At 16, he enrolled in Columbia College and received a bachelor’s degree in 1963. He then attended Yale Law School, where he was editor of The Yale Law Journal before graduating in 1966. In addition to his wife, whom he married in 1983, he is survived by his son, Abraham; his stepdaughters Martha Gehman and Abbie Britton; his sister, Alice Kelly; four grandchildren; and one great-granddaughter.