For Jo, who took voluntary redundancy in 2012 in a bid to escape the “draining, negative energy” of HM Prison Wakefield, one prisoner in particular stood out among the grotesque bunch - Michael Donovan.
The notorious Category A prison, located in Wakefield, West Yorkshire, houses some of the most malevolent men in the country's history and was once home to merciless serial killer doctor Harold Shipman, who died behind its grim walls in January 2004.
Worst prisoner in Monster Mansion - and it's not who you'd think HM Prison Wakefield has earned the chilling nickname 'Monster Mansion' due to the vile assortment of inmates caged in its cells.
Speaking with The Sun, Jo opened up about her five years working with some of the worst criminals in the UK, with her job putting her in contact with the likes of cannibal Robert Maudsley and Millie Dowler’s killer Levi Bellfield.
Donovan, who last year died from throat cancer at the age of 54, was involved in a sick fake kidnap plot with Shannon Matthews ' mother, Karen Mathews, back in 2008.
