France Shootings: Suspect Left Clues

Tim Marshall, foreign affairs editor
French police and intelligence officers hunting the Toulouse mass killer were helped by clues the suspect left behind.
After the first killing, of a paratrooper, the police set up a squad of eight cyber experts within the inquiry team. They knew the killer had contacted the first victim via computer.
On March 11, Sargent Imad Ibn Ziaten had arranged to meet a prospective buyer after placing an advertisement to sell his motorbike via a website. He had identified himself as a soldier.
The cyber squad examined the victim's computer and at first found 575 computer addresses they needed to look at in connection with the advertisement. This was narrowed down to three, with one of particular interest. It was traced to the family of Mohammed Merah.
At this point the police and the domestic intelligence service the DCRI will probably have cross referenced the family names. Merah's name can be expected to have come up as he was arrested in Afghanistan in 2010 and as he was French the authorities in Paris will have been informed. It is known he was on the DCRI's radar.
In the second and third shootings the perpetrator used a scooter which had been stolen on March 6. By now the police were sure the same man was behind all the attacks. CCTV footage showed the gunman using side streets around the town leading them to believe he was a local man.
In the second shooting, a black scooter was used. In the third, at the school, the attacker escaped on a white scooter. The police began to visit every motorcycle shop and paint shop in the city.
They then learned that a man had approached a garage asking for his black scooter to be repainted. A man had also contacted a local Yamaha dealer asking how to remove a scooter's tracking device. He had given his name - Mohammed Merah.
Late on Tuesday night, the green light was given to begin the arrest operation. In the early hours of March 21, the specialist RAID unit of the French police surrounded Merah's home. As they tried to enter it they came under fire, leading to the siege.