While a nation reacted with horror to the murder of three children and a teacher in broad daylight, police quickly made a link between yesterday's attack and the killings last week of three French soldiers of North African origin in two separate shootings.
The first incident occurred in Toulouse on 11 March when a gunman on a motorbike shot and killed a paratrooper. Four days later, a gunman opened fire on three uniformed paratroopers at a cash machine close to their barracks in Montauban, about 50km away. Two soldiers were killed while the third was critically wounded.
In all three attacks the gunman used a motorbike or scooter. In all three, he was dressed in black.
Forensic science tests showed the same weapon was used in both the Toulouse and Montauban shootings – an old US army .45-calibre revolver.
Speaking last Friday, Michel Valet, the public prosecutor of Toulouse, said: "A link has been made with certainty between the two events in Toulouse and Montauban."
After the attacks the military ordered soldiers based in and around Toulouse, which is home to the 11th paratroopers brigade, to wear civilian clothes when away from their barracks. The unexplained killings led to speculation in the French media about a potential link to the presence of French forces in Afghanistan.
The three soldiers targeted in last Thursday's attack belonged to a regiment that lost four men in Afghanistan, although the victims themselves had not served there. Police in Paris said they were also investigating threats against two synagogues in the capital from last week, but a spokesman said there was no apparent link between those threats and Monday's shootings.
Another official in Paris said the gunman knew weapons well to handle a .45-calibre handgun plus a second gun. "The shooter is someone used to holding arms," said Nicolas Comte of the SGPFO police union. "He knows what he's doing, like an ex-military guy."
In response to the attacks, the French government has tightened security at all religious schools and institutions around the country.