In August 1958, the popular CBS daytime game show "Dotto" was abruptly canceled after a contestant found a notebook containing the answers to every question that was to be asked to the show's current champion, future journalist Marie Winn. Stempel's allegations about "Twenty-One" began to gain credibility. A grand jury was convened in Autumn 1958 to investigate "Dotto" and other possible game-show fixing, investigated by Joseph Stone, the assistant district attorney of New York. Stone said in his book "Prime Time and Misdemeanors" that question writer Glorianne Rader was instructed by Dan Enright and associate producer Al Freedman, who had chosen the categories for the next broadcast earlier in the week, to place the questions in Barry's dispensing machine a few minutes before airtime; this was done to avoid any slip-ups in the planned outcome. Stone reached out to former "Twenty-One" contestants, including Richard Jackman, who confessed to the fixing of the show. Three days after Jackman's confession, and without advance public warning, "Twenty-One" was canceled after its broadcast of October 17, 1958, amid plummeting ratings. A nighttime version of "Concentration" took over its time slot the following week.