An in-depth interview with the Head of Counter Terror Policing at the time of the poisonings, Neil Basu. He relives how dangerous the investigation was for the officers involved, what it took to find the suspects, and 6 years on, how he feels about Dawn Sturgess’ death.

This episode was made by Marie Lennon, Andy Howard, Tom Ryan & Dan O’Brien.

Executive production by Mary Sanders and Naomi Wordley.