One major right Roman citizens had in the Republic was a protection against execution without trial, and immunity from certain more "degrading" executions like crucifixion. Even during the Empire citizens theoretically could petition the emperor and not be subject to summary justice...the legends surrounding the death of St. Paul claim that Paul (who, uniquely among the Apostles, was a citizen) insisted on his right as a Roman citizen to take his case before Nero and lived for years in Rome awaiting imperial judgement.

A famous breach of this immunity from summary execution was Cicero putting to death several politicians accused of conspiring with Cataline to overthrow the Republic. Cicero felt there was no time for a trial and put the men, including ex-consul P. Cornelius Lentullus Sura, to death, much to the dismay of Sura's stepson Marc Antony. Antony would later have Cicero murdered during the proscriptions of the Second Triumvirate, making a nice circle of illegal execution.