He worked days for the city street railroad while studying at night at Golden Gate College of the Law, where he graduated in 1913.

In 1922, Carter undertook complex water rights litigation on behalf of a group of farmers who complained that the Pacific Gas and Electric Company unlawfully diverted the Pit River in Shasta County.

[9] Renowned for his strongly held legal views, Carter earned the moniker the "great dissenter.

[10] In opposing the Levering Act and its ilk, Carter joined other California attorneys including UC Berkeley Dean William Prosser and Stanley Alexander Weigel in speaking out against McCarthyism.

Among Carter's most notable cases is his dissent in People v. Gonzales (1942),[11] in which he advanced the reasoning that evidence obtain illegally by the police is inadmissible in court.