Justin Freeman Shapiro, the eldest of the two children of Isadore Shapiro and Nell F. Freeman, was born in New York City on October 4, 1918. His early grammar school education was in the public schools of New York City, after which he spent two years at the Kohut School, Harrison, New York, and then three years at Phillips Academy, Andover, Massachusetts, graduating in 1936. His parents divorced while he was still young, and he later legally adopted his mother's maiden name. Following high school, he attended Yale University, New Haven, Connecticut (1936-39). In October 1940 he began service to his country in the United States Army and obtained a physical discharge in December 1941.

Following his return to civilian life he began a career as a financial and real estate reporter for the Cincinnati Enquirer. It was during this time that he became acquainted with the Dominicans and was received into the Roman Catholic Church October 3, 1942 at St. Robert Bellarmine Church, Cincinnati, Ohio, taking the baptismal name Justin Ignatius. Feeling a call to religious life and the priesthood he entered the Dominican novitiate at St. Thomas Aquinas Priory, River Forest, Illinois, in June 1945 and was given the religious name Hilary. On June 25, 1946 he made his first profession there and commenced his philosophical studies at the Pontifical Faculty of Philosophy, River Forest, Illinois. Upon making his solemn profession on June 25, 1949, he was transferred to St. Rose of Lima Priory, Dubuque, Iowa to pursue theological studies. In the course of his studies he obtained the Licentiate and Doctorate in Philosophy from the Pontifical Faculty and the S.T.Lr. from the Dominican Studium in Dubuque. On May 22, 1952, he was ordained a priest at St. Rose of Lima Priory, Dubuque, Iowa.

Father Freeman had only two assignments during his entire priestly ministry. After finishing his theological studies his first assignment was to the faculty of Fenwick High School, Oak Park, Illinois (1953-57) and then to the faculty of the College of St. Catherine, St. Paul, Minnesota, where he taught philosophy until his retirement in 1989. After his retirement from college teaching, he continued to reside at Holy Rosary Priory, Minneapolis, Minnesota, until that priory was closed in September 1995, at which time he moved to St. Thomas Aquinas Priory, River Forest, Illinois.

During his last years his health began to decline, and he was diagnosed with cancer. He continued to reside at the assisted living center at St. Thomas Aquinas Priory until July 1998, when his deteriorating physical condition made it necessary to transfer him to Resurrection Life Center, Chicago, Illinois, where he died on November 3, 1998. The funeral liturgy was celebrated at St. Thomas Aquinas Priory, River Forest, Illinois, on November 5, 1998, with burial following in the Dominican plot at All Saints Cemetery, Des Plaines, Illinois.