If Toulouse killer is not a neo-nazi, then who is he?

Criminologist: 'It is as if he is telling us that we should get ready for the worst, that he is capable of anything'

Soldiers and policemen check a passenger in a Toulouse subway station (AFP/Getty Images)

French authorities fear they may be dealing with a new and terrifying strain of serial killer: someone at once fanatical and hi-tech, calculating and inhuman.

Media speculation in the wake of the brutal attacks on a Jewish school in Toulouse on Monday had raised the possibility of a link with three paratroopers who were dismissed from the army for neo-Nazi activity in 2008. But investigators seemed to have discounted that explanation by yesterday.

Two chilling elements of Monday's attack have startled even the most hardened detectives and criminologists. First, it is almost unknown for a killer to shoot small children at point-blank range. Second, the "scooter killer" appeared to be filming himself, suggesting that he may plan to post videos of his crimes online.

Officially, all theories remain open, including a rampage by a deranged, Islamist fanatic determined to attack Jews and the army. But all the off-duty army victims last week were of Arab origin, pointing to a racist motive.

Detectives and psychological profilers believe that the scooter killer is relatively young – in his 20s or 30s. They suspect he may have a military background. He has shown great skill in his manipulation of weapons and terrifying, almost practised sang- froid in the execution of his victims. He is also, almost certainly, local to the area. Security cameras picked up his stolen scooter weaving through little-known backstreets as he escaped from his first attacks on paratroopers last week in Toulouse and Montauban.

Mr Sarkozy and his Interior Minister, Claude Guéant, admitted that investigators had little to go on. "We have nothing, except an obligation to succeed," President Sarkozy said, when questioned about the progress of the manhunt.

Yves Bianco-Brun, a criminologist at the University of Bordeaux, said it was especially disturbing and unusual that the "scooter killer" should have switched from point-blank murders of soldiers to similar attacks on children. Usually, serial killers stick to one pattern of crime. "It is as if he is telling us that we should get ready for the worst, that he is capable of anything," Mr Bianco-Brun said. "There are lots of precedents for people planning massacres but, as far as I know, nothing like this. It is terrifying."

The killer was wearing a GoPro-type automatic camera, capable of filming wide-angle footage. There is no known precedent for a serial murderer filming his crimes in this way. Pierre Lamote, a criminal psychologist, said: "This goes beyond cynicism. It suggests that he believes he is on a mission and will therefore continue."