Serial killer Joanna Dennehy's warped plot to escape jail by amputating guard's finger
![Serial killer Joanna Dennehy's warped plot to escape jail by amputating guard's finger](https://i2-prod.mirror.co.uk/incoming/article33050459.ece/ALTERNATES/s615/1_Joanna-Dennehy-court-case.jpg)
Psychopath Joanna Dennehy is serving a life sentence for murdering three men 'just for fun' and planned an horrific attack on a prison guard in an attempt to escape jail