He wrote about a number of high-profile cases in the UK, including James Hanratty, Sion Jenkins, Jeremy Bamber, Charles Ingram, Jonathan King, and Barry George.

In 1999, he was instrumental in winning a case against the Home Secretary that established the right of prisoners in the UK claiming wrongful conviction to receive visits from journalists.

For many years he produced the TV documentary series First Tuesday, and wrote for several British media publications, including The Guardian, the New Statesman, the Daily Mail, and the prisoners' newspaper Inside Time.

The film put forward evidence to show that the scientific investigation was a cover-up and that the real cause of the disaster was not cooking-oil, but organo-phosphate pesticides on tomatoes.

The Forensic Science Service successfully argued that the new tests conclusively proved Hanratty's guilt, and an appeal in 2002 was thus rejected.

In 2002, with writer Richard Webster, Woffinden helped to win the landmark case of Dawn Reed and Chris Lillie, two nursery nurses who had been portrayed as guilty of abusing children in their care by a Newcastle City Council report.

– drew attention to a possible miscarriage of justice in the case of three people convicted for cheating their way to the top prize on the UK game show Who Wants to Be a Millionaire?

In collaboration with James Plaskett, he published a book about the case, Bad Show: The Quiz, the Cough, the Millionaire Major, in January 2015.