The 27 year old is serving a life sentence in a maximum security jail in Kumla, west of Stockholm.
In September 2003 Mijailovic stabbed Lindh repeatedly as she shopped at a department store in the capital and was sentenced the following year.
In September 2005, exactly two years after the bloody attack, Mijailovic spent one month at a psychiatric unit in the northern Swedish town of Sundsvall after his mental health deteriorated.
While there, he attacked a patient with a piece of metal from a radiator. The patient sustained multiple wounds to the head and had to have a fingertip amputated.
Mijailovic has pleaded guilty to the attack through his lawyer.
Mijailovic, who has a history of mental problems, claimed during his three trials that he heard ”voices” telling him to attack Lindh.
However he insisted he did not mean to kill her and had no motive.