The suspect was friends with key figures in the extremist Islamist group Hizb ut-Tahrir, including its leader in Sweden, and shared ISIS propaganda.
Akilov revelled in his support for the group and voiced his approval at its fanatical beliefs.
He also publicly supported Bilal Philips, a well-known Canadian Muslim preacher who has appeared to condone suicide bombing and has claimed there can be no rape in marriage.
But Akilov also dreamed of living a life of luxury – on one occasion sharing a picture of a plump sultan lying on a mattress eating grapes, with eight women wearing veils waiting on him.
He wrote: 'I would like to live that way. Not bad, brother!'
Akilov allegedly told a friend about his plans to carry out the atrocity days earlier.
'By tomorrow night I'd like to find a big car and to drive into the crowd,' he allegedly wrote.
He was captured after tip-offs from the public about a man who was confused and acting strangely in the suburb of Marsta, close to the international airport.
When his friend asked him how he was, Akilov is said to have replied: 'Bad, I have driven over several people, the car drove the wrong way. I am in the airport now, dead end.'