In Conway v. California Adult Authority et al., the U.S Supreme Court addressed a case involving an inmate, Robert Lee Conway, who was denied parole by the California Adult Authority and sought habeas corpus relief in federal court. He claimed that his constitutional rights were violated because he wasn't given access to certain files used by the parole board during their decision-making process. The District Court dismissed his petition without hearing evidence or making findings of fact regarding whether due process had been violated. On appeal, the Ninth Circuit affirmed this dismissal but did not address any constitutional issues raised by Conway's claim. The Supreme Court reversed these decisions and remanded for further proceedings on two grounds: first, it held that a state prisoner may seek federal habeas corpus relief if they are held in custody in violation of their federal rights; secondly, it ruled that before dismissing such petitions without evidentiary hearings or factual findings about potential violations of due process rights (like those alleged here), courts must ensure prisoners have had full and fair opportunities to develop their claims at state level.

In the dissenting opinion for Conway v. California Adult Authority et al., Justice Douglas argued that the petitioner's constitutional rights were violated due to a lack of counsel during his parole revocation hearing. He asserted that, as per Gideon v. Wainwright and Miranda v. Arizona, an individual has a right to legal representation in all criminal proceedings where their liberty is at stake - including parole hearings. The majority ruling held that these cases did not apply because they dealt with trial situations rather than post-conviction matters like parole revocations; however, Douglas disagreed with this distinction and maintained it was irrelevant when considering basic constitutional rights such as access to counsel.