The calm, cold determination and deadly efficiency of the gunmen who attacked a French satirical magazine on Wednesday, leaving 12 people dead, has led police to believe they received military-style training.
Images of the attack on the Charlie Hebdo offices, taken on cellphones, show a carefully planned and professional operation, said a former bodyguard and policeman, speaking on condition of anonymity.
"It is obvious from the way they hold their guns and proceed calmly, coldly. They certainly received some kind of military training," said another police officer.
"They weren't acting on the spur of the moment."
In particular, he pointed to the way they held their Kalashnikov rifles close to their bodies, firing off shot by shot instead of a burst of gunfire, saying this showed they knew how to use the weapon.
The former bodyguard said: "The most striking thing is their cold-bloodedness. They were trained in Syria, in Iraq or elsewhere. Maybe even in France but one thing is sure: they were trained."
Another sign of the killers' sang-froid was seen as they struggled to find their target, first stopping at the wrong address.
"They didn't lose it and start firing. They kept on to the headquarters of Charlie Hebdo."
One video taken from the roof of a neighbouring building shows the two shooters were very well-equipped and were dressed in black, wearing masks and military-style vests.
As they fled the scene they came across a policeman on a bicycle, got out of their car and shot him dead.
One of them then approached the body and fired a shot into the policeman's head before calmly getting back into the car.
