In court, the families of riot victims protested as the Congressman's acquittal was announced. A man named Karnail Singh threw a shoe at the judge and has been arrested.
An eyewitness in the case, Jagdish Kaur, who claims to have seen Sajjan Kumar leading a mob that killed her husband and father 29 years ago, broke down in court.
Outside court, an elderly man said, "Where do we go now? How much longer do we fight for justice. It's been 29 years. We have gone from being young men to old." "Today," he said, "is worse than 1984." The families of the victims have said they will appeal against the verdict.
In its concluding arguments in the case last week, the CBI had told the court that there was a conspiracy of "terrifying proportion" between Mr Kumar and the police during the riots 29 years ago.
The Delhi cantonment riots case was registered against Sajjan Kumar in 2005 on the recommendation of the Nanavati Commission. The CBI had filed two chargesheets against him and the other accused in January 2010.
Mr Kumar, who was then the Congress MP from Outer Delhi, is also accused of instigating a mob during riots in the Sultanpuri area. Six people were killed in the violence there.
The Delhi High Court deferred a decision in that case yesterday and posted the next hearing for May 15. The High Court is hearing Mr Kumar's petition challenging a trial court order to frame charges against him in the Sultanpuri case. He is accused of murder and rioting and spreading enmity between two communities in that case. He is also facing trial in another case related to anti-Sikh riots in the Nangloi area of Delhi.
In 2010, the Supreme Court had refused to quash charges against Mr Kumar and said the trial would continue against him. It had also pulled up the CBI for failing to conclude its arguments and taking too much time.
Earlier this month, a Delhi court reopened an anti-Sikh riots case against another Congress leader Jagdish Tytler. He is accused of inciting a mob that killed three men during the riots.
The 1984 anti-Sikh riots broke out after the assassination of then Prime Minister Indira Gandhi on October 31, 1984. 3000 Sikhs were killed in Delhi alone. In the 29 years since the riots, only 30 people have been convicted, none of them high-profile politicians, though several Congress leaders have been accused of inciting violence.