Update: On August 31st the court sentenced Mayaben Kodnani, among others, to 28 years' imprisonment CHEER the determination of the special designated courts, deployed to Gujarat to investigate one of the most horrific massacres to take place in independent India. On August 29th a court sitting in Ahmedabad, the largest city of the western Indian state, convicted 32 people of murder and conspiracy, over the Naroda Patiya massacre of February 2002. Most striking, one of the convicts is a notable female politician from the state’s ruling Bharatiya Janata Party (BJP), whose more senior leaders now risk being tainted by accusations of complicity in a spectacle of mostly anti-Muslim violence. The particular massacre was the worst single incident during the three days of pogroms in 2002. In all over 1,000 people were killed in carefully organised communal violence that followed a fire on a train in the town of Godhra, in which 59 Hindu pilgrims had died. During the rioting that ensued police stood by—or even helped—the mostly Hindu mobs who attacked their Muslim neighbours in their homes. Narendra Modi, then and still the chief minister of Gujarat, and a star within the BJP, has ever since been forced to deny that he deliberately enabled the massacres by turning a blind eye to them. The killings at Naroda Patiya, a mixed Muslim-Hindu area on the edge of Ahmedabad, were sustained and gruesome. The official record of the death toll that day read: “About 95 Muslims, including 30 Men, 32 Women, 33 children and newborn children were killed and burnt”. Convincing investigative reporting by Tehelka magazine suggested that the toll was probably much higher yet, but that evidence was destroyed by fires, and by the police: bundles of body parts were dumped in other parts of the city. Many of the women and children were raped before being murdered. Tehelka gathered chilling testimony from the killers, who bragged about their deeds.

This week’s convictions (sentencing to follow on August 31st) matter for politics too. Mayaben Kodnani (pictured above, in 2009), a member of the state legislative assembly for the BJP, was described by multiple witnesses as a firebrand who was present and active at Naroda Patiya, distributing weapons, urging on the killers and even firing a pistol. Her claim that she was attending a session of the assembly that morning was, in the end, not believed.

The problem for Mr Modi is that he chose to make Ms Kodnani a minister in his state government, between 2007 and 2009. By then the accusations against her were abundantly clear, even though she had not yet been convicted. She resigned from the government when arrested, in 2009, but has since continued serving in the party and as a local MP.

Her conviction adds credence to the idea that the killers responsible for the mob violence in 2002 expected, and got, a measure of support from leading officials and politicians, who themselves were enraged by the deaths of the pilgrims on the train. Though Mr Modi himself has been cleared of legal wrongdoing by other investigations, he continues to refuse any offer of regret or apology for the awful events of 2002. He claims he bore no responsibility for what happened. Among many Indians, this deepens the impression that he is a virulent Hindu nationalist with no sympathy for the Muslim victims.

In the course of a long interview with The Economist this month, to be published soon, Mr Modi discussed his response to the riots of 2002. He argued that while it is fair to criticise him as a leader, making repeated allegations against him over the 2002 riots is illegitimate. He also claimed that the voters of Gujarat, by re-electing him frequently ever since, had given him a clean chit over the riots. That concept of popularity-as-justice looks blunt and self-serving. It will do nothing to reassure those who worry about his attitudes towards minorities.

State elections are looming in Gujarat, and Mr Modi and the BJP expect with confidence to be re-elected. That looks likely, given his efficient reputation and Gujarat’s good record at drawing investment, creating jobs and lifting agricultural output. It helps that, since 2002, the state has been calm and generally free of communal tension.

The court’s ruling, however, could help to enshrine a broader public view of Mr Modi as somebody who cannot be trusted to represent all of India. Gujarat’s chief minister would like to be India’s prime minister, and believes that he could do much to improve the economic environment and to promote more rapid development in the rest of the country. Polls suggest he could be the most popular candidate to stand for prime minister after the general election due in 2014. He seems to outshine Congress’s diffident young scion, Rahul Gandhi, for instance.

But if the BJP were to promote him as its leading candidate it would risk making the next election a referendum on Mr Modi, potentially uniting opposition to him and distracting attention from the assorted woes of Congress.

Yet it seems unlikely that this court ruling will have much impact more than a year from now. The riots in Gujarat were awful, but in the intervening years the state has prospered and stayed peaceful. By contrast, in Congress-run Assam this summer dozens of people have been killed, and hundreds of thousands displaced because of rioting and pogroms as Muslims and Bodo tribesmen clash. Again the police and officials in the state are accused of reacting too slowly and allowing victims to be killed. Congress, naturally, says it had no part to play in encouraging such violence. But these events make it harder to paint Mr Modi of Gujarat as being uniquely wicked.

Add to that the concern over other massacres and riots in the 1980s, not only in Assam, but also what befell Sikhs in Punjab and Delhi following the assassination of Indira Gandhi by her bodyguards in 1984. After Mrs Gandhi’s killing, retaliation against entirely innocent Sikhs was allegedly tolerated and even encouraged by police and officials, under the guidance of Congress. No court has ever held anybody accountable for that.