meanwhile, kouachi's old associate amedy coulibaly had just been released from prison.rench domestic intelligence now decided to stop watching them and shift surveillance resources onto the growing threat from isis. >> (translated): for more than three years the surveillance and wiretappings had yielded nothing, so it was stopped at that time. this was mid-2014, which means that for six months, the services didn't know what the kouachi brothers were up to, and didn't know about the alliance they developed with amedy coulibaly, who had never been monitored since he stepped out of prison. (man shouting) (gunfire) >> breaking news out of france. the french police right now are hunting for masked gunmen who stormed the offices of the satirical newspaper, opened fire in the french capital today. at least 12 people are dead, four others are in critical condition. >> (translated): charlie hebdo was a turning point. the concept of attacking in the heart of europe was a new expression of terrorism. we realized that it was now a reality. >> narrator: 12 people were shot dead in t

amedy coulibaly rved only three years for his involvement in a plot to help a convicted terrorist escaperom prison. no one else in the buttes- chaumont crew served more than seven years, even dangerous fighters who saw combat in iraq. today several are active terrorists. >> (translated): the judges did not realize that these people were time bombs. they didn't rightly assess their truly dangerous nature. consequently, they were given light sentences, perhaps to try to reintegrate them into society. >> (translated): we were mistaken in our assessment of quite a lot of people who we thought were less dangerous than they actually were. from the moment they stepped out of prison they left with an even greater hatred towards france than before. we only increased their wish for revenge and their determination to hurt us. >> narrator: having already spent 20 months in prison awaiting his trial, kouachi left court a free man. by this time, louis caprioli had retired. >> rotella: for a police officer like you, who has worked to put these people in jail, how does that make you feel? >> (translated