The Innocence Project is a legal aid group that aims to exonerate those who have been wrongly convicted of crimes.  Speaking to Sean O'Rourke on the Today programme about the work they do was Anne Driscoll who got involved as an investigative journalist.  She gave Sean an example of a case she had worked on while at the Schuster Institute for Investigative Journalism in Brandeis University in Massachusetts.

"Angel had been wrongfully convicted of a murder.  He spent 21 years in prison.  He would have died in prison had this effort not been made on his behalf and so I worked on his case for nearly 10 years and I was able fortunately to find evidence that the prosecution had withheld."

Anne warned of the perils of eyewitness misidentifications.  "Sadly, about 75% of the cases that have been overturned based on DNA evidence involve wrongful IDs," she told Sean.

"Most crimes happen quickly, they might happen in the dark, people are in distress, there might be a weapon involved and so they're focused on that weapon so all of those factors contribute to the fact that people often mistakenly ID someone and I'm well aware of that because I have seen what happens to people who are wrongfully convicted, people like Angel."

Also speaking to Sean was David Rudolf who listeners might recognise from the much-publicized Netflix series 'The Staircase'.  It followed the story of Michael Peterson who was charged with the first-degree murder of his wife Kathleen.

"I represented Michael all the way through his trial and from investigating the case, it was clear to me that theory that the prosecution had was completely nonsensical.  The evidence of his involvement was almost non-existent, it was all circumstantial evidence and it was all based on blood spatter expert that the prosecution had put up on the witness stand and 'junk science' is what I call it.  It's forensic evidence that really has very little basis in scientific principals and… it's designed basically fill in the holes that otherwise exist in a prosecution's case."

Click here to listen to Today with Sean O'Rourke.