Joanna Dennehy
In 2013, the 32-year-old British woman pleaded guilty to stabbing three men and dumping their bodies in a ditch in Peterborough. Before her sentencing, she wrote a letter to the judge stating she felt no remorse for what she had done. Sentenced to life imprisonment, she is only the third woman in the UK to ever be told she will spend the rest of her life behind bars. The judge called her a “cruel, calculated, selfish, and manipulative serial killer”, which was met with a smirk. She has since been diagnosed with borderline personality disorder.