But the dominant view was that Durn had killed himself.
Durn had a history of mental problems and often spoke about suicide.
Mr Rijik saved himself by diving under a table when Durn opened fire from the public gallery at the end of a meeting.
One of Mr Rijik's colleagues, Catherine Maurel, said victims' families were devastated that Durn would never face them in court.
Stephanie Durn, 68, said her son had spoken "maybe 20 times" about wanting to kill.
Jobless Durn sat through a six-hour council meeting before his murder spree.
Durn was a regular at council sessions in his middle-class neighbourhood.
Durn waited until the rest of the public left, then started shooting.
Durn belonged to a gun club but it emerged yesterday that permits for his three pistols had run out.
DEATH PLUNGE: Mass murderer Richard Durn's body lies in a courtyard yesterday at the police headquarters in Paris where he was being questioned; PROBE: Window which Durn, right, went through is ringed; Picture: REUTERS
She said Durn had talked about wanting to kill "many times .
Durn was armed with two Glock automatic handguns and a .
Durn belonged to a gun club and had licences for his weapons.