Officer talks about investigation into Notorious B.I.G's 20-year-old murder

LOS ANGELES (KABC) -- On the 20-year anniversary of the death of rapper Notorious B.I.G, an officer involved in his unsolved murder talks about the case.

One theory that has been popular is that it was in retaliation to the murder of Los Angeles rapper Tupac Shakur.

Montebello police Chief Kevin McClure, who used to head the LAPD robbery-homicide division for years, said there were constantly pieces linking Shakur and Biggie Smalls together. But he also said the case is complex.

He went on to say the actual shooter may not even be alive, based on evidence gathered in the case.

Many fans and celebrities posted tributes to Smalls on social media.