On 15 April 1848, a grand jury was called on to indict not only Mitchel, but also his former associates on the "Nation" O'Brien and Meagher for "seditious libels". When the cases against O'Brien and Meagher fell through, thanks in part to Isaac Butt's able defence, under new legislation the government replaced the charges against Mitchel with Treason Felony punishable by transportation for life. To justify the severity of new measures, under which Mitchel was arrested in May, the Home Secretary thought it sufficient to read extracts from Mitchel's articles and speeches.