The terrorist is reportedly a 39 year old man from Uzbekistan who posted ISIS video to Facebook.
He was in the country illegally.
The Uzbek Islamist was denied residence in 2014 but stayed in the country for several years free from harassment.
Fria Tider reported (rough translation):
The 39-year-old Uzbek man arrested on suspicion of terrorist attack in Stockholm on Friday would be expelled from Sweden. The police said in a news conference on Sunday. Police also confirmed that he has shown sympathy with the Islamic state.
The man applied for a residence permit in Sweden in 2014. In June 2016, he received the refusal and expulsion. But thanks to the generous regulatory framework, which allows expelled immigrants move in freedom in the country in anticipation of penalty is given, he could still remain in Sweden illegally.
In December 2016 it was announced he will leave the country in February 2017 handed over execution decision to the police. On February 24, he was wanted by the police.