When Penny Jackson was arrested for the murder of her husband, 78-year-old David Jackson, the world was stunned by her apparent lack of remorse and her concern that she may not have harmed him enough to kill him. The motivation was supposedly nothing more than an argument over her choice to serve bubble and squeak with the gourmet evening meal. How could this seemingly nondescript middle-class woman have transformed into a cold-blooded killer?

Although Penny Jackson openly confessed to police to brutally stabbing her husband to death in the kitchen of their family home, she claimed she only did so after having been pushed to her limit by a sustained campaign of abuse. It’s a claim vigorously disputed by the prosecution and by David Jackson’s sister, Jenny. But support for David’s aggressive tendencies comes from an unlikely source, who was never called to testify at trial – David Jackson’s estranged brother, Alan.