Unfortunately for you, this was not a Hindu-Sikh riot.
The massacre of Sikhs was orchestrated by the some elements within the Congress party in retaliation for the assassination of their leader Indira Gandhi. The same Congress party which calls itself the champion of secularism, and has amongst its leaders - Christians, Muslims, Sikhs & Hindus.
Congress has ruled for a majority of the time since 1984, and has suppressed the investigation in this case.