The conclusions of a professional opinion on the mental state of 21-year-old attacker Francis N. were reported in the Krone Zeitung newspaper.
According to the newspaper, the document is still officially classified but is expected to be released in the coming days.
If confirmed, it means Francis N. might be sent to an institution for mentally disturbed prisoners to receive psychiatric help, rather than to a standard prison.
The 21-year-old suddenly attacked and killed mother of three Maria E. while she was on her way to work with a colleague near Vienna's Brunnenmarkt.
Alfred Boran, the lawyer representing the victim's widower described the conclusion of the opinion to the Krone Zeitung as “a farce”. “Relatives of the victim have again no chance for fair proceedings,” he said.
Authorities were criticised following the brutal murder after it was revealed the attacker was an illegal immigrant - originally from Kenya - who was known to authorities.
The suspect came to Austria legally in 2008 but overstayed his visa and had been reported for 18 previous offences since 2010.
In 2013 he spent some time in jail after being found guilty of coercion and causing bodily injury and in May 2015 he was reported for allegedly attacking someone with an iron bar, although he was not sentenced. The victim that time was just lightly injured.
The Federal Office for Asylum was aware that the man was in Austria illegally and had ordered his deportation a few years ago but had not yet managed to carry it out.
Following the incident, Interior Minister Wolfgang Sobotka (ÖVP) immediately suggested a new bundle of new measures to fight against escalating violent incidents.