In 1965, along with Jean-Denis Bredin, Badinter founded the law firm Badinter, Bredin et partenaires (now known as Bredin Prat), where he practised until 1981. Badinter's struggle against the death penalty began after Roger Bontems's execution, on 28 November 1972. Along with Claude Buffet, Bontems had taken a prison guard and a nurse hostage during the 1971 revolt in Clairvaux Prison. While the police were storming the building, Buffet slit the hostages' throats. Badinter was the lawyer for Bontems, and although it was established during the trial that Buffet alone was the murderer, the jury sentenced both men to death. Applying the death penalty to the person who had not committed the killing outraged Badinter to the point that he dedicated himself to the abolition of the death penalty.
In this context, and as a lawyer, he agreed to defend Patrick Henry. In January 1976, 8-year-old Philipe Bertrand was kidnapped. Henry was suspected very soon, but released because of a lack of proof. He gave interviews on television, saying that those who kidnapped and killed children deserved death. A few days later, he was again arrested, and shown Bertrand's corpse hidden in a blanket under his bed. Badinter and Robert Bocquillon defended Henry, making a case not in favour of Henry, but against the death penalty. Henry was sentenced to life imprisonment but paroled in 2001.
The death penalty was still applied in France on a number of occasions (three people were executed between 1976 and 1981), but it became a matter of considerable public concern.
In 1981, François Mitterrand was elected president, and Badinter became the Minister of Justice. Among his first actions was a bill to the French Parliament that abolished the death penalty for all crimes, which the Parliament voted after heated debate on 30 September 1981.
During his mandate, he also passed several laws, such as:Abolition of the "juridictions d'exception" ("special courts"), like the Cour de Sûreté de l'État ("State Security Court") and the military courts in time of peace.
Consolidation of private freedoms (such as the lowering of the age of consent for homosexual sex to make it the same as for heterosexual sex)
Improvements to the Rights of Victims (any convicted person can make an appeal before the European Commission for Human Rights and the European Court for Human Rights)
Development of non-custodial sentences (such as community service for minor offences). He remained a minister until 18 February 1986.
From March 1986 to March 1995 he was president of the French Constitutional Council, and since 24 September 1995 he has been a senator for the Hauts-de-Seine département.
In 1991, he was appointed by the Council of Ministers of the European Community as a member of the Arbitration Commission of the Peace Conference on Yugoslavia. He was elected as President of the Commission by the four other members, all Presidents of constitutional courts in the European Community. The Arbitration Commission has rendered eleven advices on "major legal questions" arisen by the split of the SFRY.
Badinter continues his struggle against the death penalty in China and the United States of America, petitioning officials and militating in the World Congress against the death penalty.
In 1989, he participated in the famous French television program Apostrophes, devoted to human rights, in the presence of the 14th Dalaï Lama. Discussing the disappearance of Tibetan culture from Tibet, Badinter used the term "cultural genocide" and lauded the exemplarity of the Tibetan nonviolent resistance. Badinter met the Dalai Lama many times, in particular in 1998 when he greeted the Dalai Lama as the "Champion of Human Rights" and in 2008.
He recently opposed the accession of Turkey to the European Union, on the grounds that Turkey might not be able to follow the rules of the Union. Also, the geographic setting of Turkey makes it a bad candidate according to Badinter: "Why should Europe be neighbour with Georgia, Armenia, Syria, Iran, Iraq, the former Caucasus, that is, the most dangerous region of these times? Nothing in the project of the founding fathers foresaw such an extension, not to say expansion."
As a head of the Arbitration Commission he gained huge authority among Macedonians and other ethnic groups in Republic of Macedonia because he recommended "that the use of the name 'Macedonia' cannot therefore imply any territorial claim against another State" and, therefore, full recognition in 1992 . Because of that, he was involved in drafting the so-called Ohrid Agreement in the Republic of Macedonia. The principle in this agreement that ethnic related proposals in the national assembly (and later on in the city councils and other local government bodies) should be supported by a majority of both ethnic groups is often called the "Badinter principle". He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 2006.
A made-for-television film – L'Abolition (The Abolition) – was broadcast on the France 2 channel in two parts in January and February 2009 with Charles Berling in the role of Robert Badinter. The film focuses on Badinter's attempts to save the lives of both Roger Bontems and Patrick Henry and his fight to have the death penalty abolished in France.
In 2009, he expressed dismay at the lifting of the excommunication of controversial bishop Richard Williamson.
Badinter serves as an Honorary Co-Chair for the World Justice Project. The World Justice Project works to lead a global, multidisciplinary effort to strengthen the Rule of Law for the development of communities of opportunity and equity.
Badinter comes from a Bessarabian Jewish family that had emigrated to France in 1921. During World War II, his father was deported from Lyon and perished at Sobibor extermination camp. His wife Élisabeth is a feminist writer and the daughter of Marcel Bleustein-Blanchet, the founder of Publicis.President of the Constitutional Council of France: 1986–1995.
Governmental functionMinister of Justice : 1981–1986 (Resignation, became President of the Constitutional Council of France).
Electoral mandate Senate of FranceSenator of Hauts-de-Seine : 1995-2011. Elected in 1995, reelected in 2004.