Mariah Carey and Sean 'Diddy' Combs' former 44-year-old manager was found dead in his apartment here on August 30 with a gunshot wound to the head.
After completing an autopsy, the New York Medical Examiner's office confirmed that Lighty died from a self-inflicted wound.
Police have said that there were no signs of foul play, New York Daily News reported.
Stars including Carey, Combs, Rihanna, Ludacris, John Legend and Mary J Blige have all paid tribute to the hip-hop mogul.