Can an anti-Semitic killer be declared insane because his mind was affected by regular consumption of cannabis? That is the question at the heart of an explosive legal row in France following the decision not to prosecute the man who killed Sarah Halimi. Sarah Halimi was a Jewish, 65-year-old, former kindergarten director, who in April 2017 was beaten, then thrown to her death from her flat in north-east Paris. The killer was Kobili Traoré, a Muslim of Malian origin who was her neighbour. During the attack, which lasted between 20 and 30 minutes, he chanted verses from the Koran and shouted “Allahu Akbar” – God is greatest.