One of the world's most unforgivable legal scandals. How South Australia's Chief Forensic Officer operated for decades with barely a qualification, giving evidence in 400 criminal cases that saw innocent people imprisoned.

He was brave enough to stand up to the mafia in a country town. But Don Mackay paid the ultimate price. His enemies weren't just mafia living by the creed: You speak, you die. He was also facing a political insider.