One fact no one disputes in the sensational murder trial playing out this week at a small courthouse in Chalon-sur-Saone, rural Burgundy, is that the middle-aged woman who stands in the dock is a killer.

Valerie Bacot, a 40-year-old mother-of-four, has used a series of interviews, witness statements and a bestselling memoir to tell how she shot her husband (and former stepfather) Daniel Polette in the back of the neck as he turned the key in the ignition of their Peugeot 806 people carrier on the night of Sunday, March 13, 2016.