Two of the attacks are already known. They involve an attempted murder of an 80-year-old man who was stabbed multiple times in September, as well as an earlier attempted murder of a woman in July.
However, according to SVT's investigation, there are at least six unprovoked assaults that have been filmed and posted on Telegram channels linked to 764.
Several of the victims are said to be elderly and visibly frail. SVT has verified where the incidents took place using satellite images, landmarks in Hässelby, and by physically visiting the locations to compare the environment.
A 14-year-old boy has been detained on suspicion of the two crimes that the police have so far announced. According to SVT, the boy has a leading role in the Swedish part of 764 and its subgroup NLM (No lives matter).
He has confessed to the attempted murder of the 80-year-old man, according to a court decision, but claims not to have committed any other crimes.
The police do not want to comment on the investigation, citing the secrecy of the preliminary investigation, but have previously said that they are investigating whether more people may have fallen victim.
The FBI has warned about the online movement 764, which glorifies violence and has, among other things, forced children to engage in self-harm. The name comes from the founder's postal address in his hometown of Stephenville. The founder, a teenager, is currently serving an 80-year prison sentence for child pornography offenses.