It's been 27 years since rapper Tupac Shakur was shot near the Las Vegas Strip, dying in hospital less than a week later. No charges were ever laid – that is, until Friday, when the police arrested long-time suspect Duane "Keefe D" Davis.Today, author and journalist Santi Elijah Holley explains how the Shakur legacy continues, and weighs in on the question we're all asking about the investigation: what took so long?