Alistair Scrutton and Frank Jack Daniel AHMEDABAD, India — Amit Shah is charged with three counts of murder. He is also a key election campaign manager and close aide of Narendra Modi, the frontrunner to become India's next prime minister. To supporters, Shah's proven talent in winning elections makes him the obvious choice to run Modi's campaign in Uttar Pradesh, a swing state that holds the key to national power. But for critics, Modi's ties to Shah are proof that there is a dark side to the Hindu nationalist leader now storming ahead in opinion polls on promises to sweep away corruption and economic mismanagement. Modi's popularity stems in large part from his record of governance as chief minister of Gujarat state, an economic powerhouse. But he himself is dogged by accusations that he turned a blind eye to sectarian riots in Gujarat, in which at least 1,000 people – mainly Muslims – were killed in 2002. He denies any wrongdoing and the Supreme Court has said there is not enough evidence to proceed against him. “We were shocked,” said Mukul Sinha, a lawyer representing relatives of victims in the cases against Shah, commenting on his appointment as campaign manager for the Bharatiya Janata Party (BJP) in Uttar Pradesh, the country's most populous state. “This man faces criminal charges. But if Modi wins, he could be one of India's most powerful politicians,” he said, referring to the possibility that Shah could become a senior federal minister. An election due by May will pit Modi's BJP against the Nehru-Gandhi dynasty's Congress party, whose popularity has wilted after two terms in power amid a sharp economic slowdown and corruption scandals. The BJP says Congress and other parties pander to minorities for votes. Congress counters that Modi and the BJP are biased, especially against Muslims. A stocky, bearded figure and son of a well-to-do businessman, Shah was interior minister for seven years in Gujarat before his 2010 arrest and subsequent release on bail. Shah denies charges that he ordered the killing of a man police claimed was a militant on a mission to assassinate Modi. The man's wife and a witness were also killed. “This is a politically-motivated campaign,” said BJP spokeswoman Meenakshi Lekhi. Shah and his lawyers did not respond to requests from Reuters for an interview, but last year he said the case was a political vendetta. “All of this is being done to defame Chief Minister Modi, me and the BJP,” he told Times Now TV, arguing that similar killings elsewhere in India were not subject to probes. In a chargesheet seen by Reuters, the CBI says while he was interior minister, Shah ran an extortion racket with Gujarat police officers and Sohrabuddin Sheikh, the suspected militant. They fell out and police snatched Sheikh from a bus with his wife, then staged a gun battle, the chargesheet said. Sheikh was killed and his wife's cremated body was found in the village of one of the policemen. The witness was killed later. According to the charges, phone records show Shah had multiple calls with the accused officers during the operation. Gujarat police said Sheikh had links with the Pakistan-based militant group Lashkar-e-Taiba, but the state government later told a court that police had staged the gun battle. Activists have long tried to link Shah to a separate case of extra-judicial killing involving the same police officers, but the CBI has said there was not enough evidence to charge him in that case. — Reuters