Kehar Singh was tried and executed for conspiracy in the plot of the Indira Gandhi assassination, carried out by Satwant Singh and Beant Singh. He was hanged in Tihar Jail on January 6, 1989. Beant Singh was the nephew of Kehar Singh. The assassination was motivated by Operation Blue Star which was carried out starting on 3 June 1984, the military action against the Sikh "Golden Temple" in Amritsar at Sikhism's holiest shrine. These violent events which led to the desecration of the holy shrine Golden Temple / Harminder Sahib caused outrage amongst the Sikh community, who claimed that the attacks were pre-planned and that anti-Sikh violence which followed was government orchestrated. Beant Singh and Satwant Singh were Sikh bodyguards of Indira Gandhi, and on 31 October 1984 they assassinated her in her garden, putting thirty three bullets in her chest and abdomen.
Beant Singh was killed by gunfire at the scene of the assassination. Satwant Singh was arrested and Kehar Singh was later arrested for conspiracy in the assassination. Both were sentenced to death and hanged in Tihar jail in Delhi.
Honours and death anniversaries 
Again, On January 6, 2008 the highest Sikh temporal seat (Akal Takhat, Amritsar) declared Kehar Singh and other assassins of former prime minister Indira Gandhi martyrs of Sikhism. SGPC also paid homage to both Satwant Singh and Kehar Singh and called them "martyrs of Sikh nation". Shiromani Akali Dal observed their death anniversary as 'martyrdom' on October 31, 2008