Under changes to the murder laws announced this week, the defences available to women on trial for murder who have killed a partner as a result of domestic violence are to be widened and clarified; whereas men who kill their wives claiming that they were provoked into it because of her "nagging" or alleged infidelity will find that they have far less sympathy from the courts.

These are welcome reforms but for many women, including my friend Emma Humphreys, it's come much,...