Police say the suspect also planned to kill the leader of Sweden's Centre Party.
A Swedish man has been charged with "terrorism" after killing a woman near a political festival on the island of Gotland in July.
The 33-year-old suspect was arrested after fatally stabbing prominent psychiatrist Ing-Marie Wieselgren, who worked as a coordinator for the Swedish Association of Local Authorities and Regions.
Police said there were indications the man also wanted to murder Centre Party leader Annie Lööf, who was on the island and has long been a target of far-right groups.
A court-ordered psychiatric assessment found that the man was mentally ill at the time of the murder. He had acquired a knife, two swords, and a bow and arrow before the attack.
Investigators also say he also had detailed information about the plans and movements of both Wieselgren and Lööf during Almedalen.
Prosecutors say the killing planned to "cause serious fear among the population" in Sweden and have labeled it an act of "terrorism".
The trial is expected to start on 8 November.