He received his doctoral degree in juridical sciences in 1969 by defending a thesis "Bourgeois Legal Ideology: a Critique of the Teachings of Law".

In December 1993, Tumanov became a deputy of the 1st State Duma (Party of Russian Unity and Accord), where he joined the Committee for Legislation and Judicial Reform.

A year later, Tumanov was appointed judge of the Constitutional Court of Russia, so he stepped down as MP.

In February 1997, Tumanov resigned as court president due to the attainment of the maximum age, but kept office of the ordinary judge.

[2][3] In April 1997 he was appointed judge of the European Court of Human Rights during the PACE session.