Following on from his painfully amateurish Kurt and Courtney, British documentary maker Nick Broomfield turns his attention to another pair of modern musical icons. Here he investigates the unsolved murders of US rap stars Tupac Shakur and Christopher Wallace (aka Biggie Smalls, The Notorious BIG.), throwing up allegations of conspiracy, corruption and police complicity in the killings. With a sound unit strapped satchel-style across his chest, Broomfield comes across as a diligent scholar. Doggedly chasing his interview subjects, he's both relentless and meticulous in his approach, and for this he's rewarded with some fascinating, though sometimes questionable, testimonies. Broomfield's gaffes and preambles are included, as in his previous projects, but the assumed air of bumbling incompetence gives the film an inappropriate and unintentionally humorous touch, and weakens the power of his case. While his no-frills technique and faux naivety may have served him well in the past, with Biggie and Tupac, Broomfield has finally descended into the realm of self-parody.