Excerpt:
French authorities contend the gunman in a killing spree in Toulouse took the path to religious radicalization behind bars, with neither teacher nor network.
The investigation will show whether gunman Mohamed Merah, who claimed al-Qaida links, acted alone in the three March attacks that killed seven people, and may help decipher his path to radical Islam.
But in the meantime, his case has been seized upon by those who say the model for Islamist radicalization in prisons may be changing, away from networks of extremists and toward more individualized paths to radicalism.