His forced recusal from the case brought by the widow of Giuseppe Pinelli against the police commissioner Luigi Calabresi in 1971 became a cause célèbre.
Biotti was the presiding judge in the case brought by the widow of Giuseppe Pinelli against the police commissioner Luigi Calabresi.
Neither Biotti nor his two fellow judges were convinced that Pinelli had died from falling from the police station window.
His forced recusal not only prevented the exhumation of Pinelli's body, but delayed the investigation for two years.
In the 2012 film Piazza Fontana: The Italian Conspiracy, the character of Carlo Biotti is played by Bob Marchese.