Gustin Lewis Reichbach was born in Brooklyn, New York on October 9, 1946. His mother, Lee Reichbach, was a retired public school secretary. His father, Herman Reichbach, was a machinist. Justice Reichbach married Ellen Meyers on October 24, 1984. They had one child together, a daughter named Hope I. Reichbach, who was born in 1988. Hope Reichbach passed away in 2011.

Reichbach attended Junior High School 240 in Brooklyn, class of 1960, and Midwood High School, class of 1963. As an undergraduate he attended The State University of New York at Buffalo, graduating in 1967. He was president of Alpha Epsilon Pi and graduated with a B.A. in political science, magna cum laude, Phi Betta Kappa.

After traveling to Israel in the summer of 1967 he enrolled at Columbia University School of Law. Reichbach completed his J.D. in 1970. While at Columbia University he was active with the Students for a Democratic Society (SDS), where he organized protests and occupations on campus in 1968. During one protest Reichbach was arrested for disorderly conduct, placed on probation, and eventually acquitted after a raucous trial on campus. His involvement with SDS and with the subsequent co-authorship of a book titled "The Bust Book: What to Do Till the Lawyer Comes" which was published in 1970, significantly delayed Reichbach's admittance to the New York State Bar Association because of interest shown in these issues by the Committee on Character and Fitness and testimonies against his character submitted by law school faculty.

Reichbach passed the New York State bar exam in 1970 but it took fourteen month before he was admitted in 1972. He was later admitted to the State Bar of California, the United States Supreme Court, and various United States District Courts including the Eastern and Southern Districts of New York. As a lawyer he specialized in landlord tenant and real estate law, criminal defense law, entertainment and publishing law and labor law.

While at Columbia University Law School, Reichbach worked as a law clerk at Lefcourt, Cohen, Garfinkel and Lefcourt. Between graduation and admittance to the bar, Reichbach continued to work with Lefcourt and the New York Law Commune; a collective of activist lawyers, where he represented the New York Black Panthers, Abbie Hoffman and anti-war demonstrators. After his admittance to the New York State Bar Reichbach established his private law practice and remained in New York until he moved to California to serve as Counsel to the California Agricultural Labor Board for two years beginning in September 1976. While in California he also maintained a private law practice.

Reichbach returned to New York in December 1976 and reestablished his practice. He won significant cases in landlord and tenant law including one that legalized residential loft life in SoHo and TriBeCa.

Reichbach was elected to The Civil Court of the City of New York in January 1991 after running against the established party. During his short tenure on the criminal night court he created a controversial HIV testing and counseling program that was made available to defendants. This program earned him the nickname "The Condom Judge" by the New York Post. Reichbach was soon transferred to civil court but his testing and counseling program was eventually restored.

Reichbach was elected to the New York State Supreme Court (Kings County) in 1998. During his tenure on the bench Reichbach presided over various capital murder trials, a significant Medicaid fraud case, and the well-publicized bench trial of FBI agent Roy Lindley DeVecchio.

Reichbach also served as an International Judge for the United Nations Interim Administration Mission in Kosovo (U.N.M.I.K.) and for the Kosovo Supreme Court in 2003 and 2004, respectively. During his time in Kosovo he presided over war crime trials and appeals.

Upon his return from Kosovo Reichbach resumed service on the New York State Supreme Court and remained in this capacity until his death from cancer in 2012.

In 2013 the Kings County Criminal Defense Bar named their annual judicial recognition award the Gustin L. Reichbach Judicial Recognition Award.