Anger over the treatment of demonstrators following the death of Benno Ohnesorg and the attack on Rudi Dutschke, coupled with growing frustration over the lack of success in achieving their aims, led to growing militancy among students and their supporters. In May 1968, three young people set fire to two department stores in Frankfurt; they were brought to trial and made very clear to the court that they regarded their action as a legitimate act in what they described as the 'struggle against imperialism'. The student movement began to split into different factions, ranging from the unattached liberals to the Maoists and supporters of direct action in every form—the anarchists. Several groups set as their objective the aim of radicalizing the industrial workers and, taking an example from activities in Italy of the Brigade Rosse, many students went to work in the factories, but with little or no success. The most notorious of the underground groups was the 'Baader-Meinhof Group', later known as the Red Army Faction, which began by making bank raids to finance their activities and eventually went underground having killed a number of policemen, several bystanders and eventually two prominent West Germans, whom they had taken captive in order to force the release of prisoners sympathetic to their ideas. The "Baader-Meinhof gang" was committed to the overthrow of the Federal Republic via terrorism in order to achieve the establishment of a Communist state. In the 1990s attacks were still being committed under the name "RAF". The last action took place in 1993 and the group announced it was giving up its activities in 1998. Evidence that the groups had been infiltrated by German Intelligence undercover agents has since emerged, partly through the insistence of the son of one of their prominent victims, the State Counsel Buback.