The 40-year-old suspect has studied and worked as a journalist in Stockholm, Gothenburg and Uppsala, French and Swedish media reported.
"The man worked as a freelance journalist for different newspapers and radio in Sweden between 2009 and 2010," Arnaud Mercier, a professor in political communication at the university Paris 2 Assas, told Swedish newspaper Aftonbladet. He later received a Master degree at the University of Uppsala, Mercier added.
The man attacked a police officer with a hammer by the Notre Dame cathedral before he was shot by police and brought to a Paris hospital on Tuesday afternoon. The police officer received minor injuries.
Documents that the man was carrying on him at the time of his arrest showed that he is an Algerian PhD-student at a French university. A well-known French media and journalism researcher has described him as “meek as a lamb” and suggested that what happened by the Notre Dame cathedral was “an act of madness”.
According to the news agency AFP, a spokesperson for the French government said that the attack is being treated as an "isolated incident" and that the man had "never shown any signs of radicalisation". However, AFP also quoted a source as saying that the 40-year-old had pledged allegiance to the Islamic State in a video found in his apartment.
The man apparently left Sweden in 2013 and returned briefly to Algeria before moving to Metz in France for his doctoral studies.
A spokesperson for the Swedish intelligence and security service, Säpo, told news agency TT that the man is not previously known to them but that they are monitoring the case closely.