"Michael had a wonderful memory for people, places and facts," said his son, Hugh, of Huntington. "He could remember a person's name he had met 10 years ago and was able to continue the conversation they started 10 years prior."
O'Brien, who was raised in Brooklyn, earned his bachelor's degree from St. John's University in Queens in 1958 and was soon teaching English at St. John's Preparatory School in Brooklyn. Between there and Sewanhaka High School in Floral Park, he taught until 1966, a year after receiving a master's degree from New York University.
In 1966, he became coordinator of training for Nassau's Department of General Services. In 1976, he became the county's Energy Office director.
He also earned his law degree from St. John's that year, and, in 1977, he went into private practice.
But from 1980 to 1982, he was a staff attorney for the state's Division of Criminal Justice. While there, he was also assistant editor and contributor to the New York State Criminal Law Review. He then served as a Queens assistant district attorney until 1992.
Hugh O'Brien said his father was a poet and had "a quick smile and sharp wit," and that he loved to read.
"He made weekly trips to the local library," he said.
Survivors also include three more sons, Michael of Pacifica, Calif., Bernard of Los Angeles and William of Argyle, N.Y.; a daughter, Moriah Gillis of West Hartford, Conn.; and eight grandchildren, including one who was born the day after he died.
Viewing will be from 2 to 4 p.m. Sunday and from 2 to 4 p.m. and 7 to 9 p.m. Monday. A funeral Mass will be offered at 10:45 a.m. Tuesday at the Church of St. Patrick in Huntington.
Interment will follow at St. John's Cemetery in Middle Village, Queens.