A Channel 5 documentary into Harpenden serial killer Joanna Dennehy will air tonight, almost a year after she was jailed for life.

‘Killer Psychopaths’ will look into the case of Dennehy, who killed three men in Peterborough in late March 2013.

The show, presented by criminologist Professor David Wilson, will speak to people connected with Dennehy, her accomplices and her victims, as well as taking viewers on a journey through her life to find out what made her tick.

Dennehy was born in Harpenden and attended Roundwood Park School.

The 32-year-old mother-of-two, who left her family’s £315,000 four-bedroom home in St Albans at 16, became one of just three women in Britain who have been told they will die in jail - joining Moors Murderer Myra Hindley and Rose West.

‘Killer Psychopaths’, the first in a six part series looking at a number of murderers in the UK and the USA, will be shown at 9pm tonight.