Open-source investigators forensically analyse digital evidence - social media posts, eyewitness videos, satellite imagery, to find the truth behind news events. Their techniques are now increasingly used by investigative journalists to achieve big impact. An investigation by The New York Times into civilian deaths from air and drone strikes has resulted in a policy change by the US military. Also in the programme - in the west it is headlined as the Ukraine crisis, but how is the situation being reported in Russian and Ukrainian media?