NEW DELHI - For a politician running on a platform of clean government, having a key aide facing murder and extortion charges could be seen as a liability - but not by the man tipped to be India's next prime minister.
Narendra Modi, the hardline Hindu nationalist leading the opposition Bharatiya Janata Party (BJP) into elections this week, first met former stockbroker Amit Shah in the 1980s when both of them were volunteers.
Over the years, Shah, a portly and bearded 50-year-old, has become his closest confidante and key political manager. He is widely expected to take a senior role in any future Modi-run administration.
"Everyone in the party understands that the shortest path to Modi goes via Shah," said one party insider, who spoke to AFP on condition of anonymity.
The married father of a son was in the eye of a storm at the weekend after reportedly telling supporters to see India's parliamentary polls as an opportunity for "revenge" against the left-leaning ruling Congress party.
Speaking in an area torn apart by sectarian hatred last August, he will face a criminal investigation after branding the government as one "that protects and gives compensation to those who killed Hindus".
More than 50 people died in the district of Muzaffarnagar in the state of Uttar Pradesh, where several BJP members were already facing charges of inciting violence against Muslims.
Modi is reviled by many of India's Muslims due to religious riots in Gujarat in 2002 when he was chief minister. At least 1,000 people, mostly Muslims, were killed.
In May 2013, Shah was appointed chief strategist for Uttar Pradesh, where the BJP must triumph for Modi to stand any chance of emerging as India's next prime minister when results are announced on May 16.
Opponents, including Minority Affairs Minister Rahman Khan, accused him of trying to polarise voters and even deliberately stoking tensions in a state with a long history of sectarian killings.
"What I can tell you is that there is a Modi wave not just in Uttar Pradesh but across the country," Shah told AFP on sidelines of an event in Delhi in March.
The latest polls show the party likely to win more than half of the 80 seats up for grabs, but it has faced criticism for fielding two candidates linked to the Muzaffarnagar riots.
"Obviously, he (Shah) is one of our wisest political heads and the man in charge of UP. He would be giving key inputs for candidates' nomination," a senior party leader told AFP on condition of anonymity.
A master strategist
Even those colleagues who resent his aloofness acknowledge Shah's acumen and respect his unflinching loyalty to Modi. His patron has reciprocated, sticking by him through multiple scandals.
The biggest of those stems from the alleged extra-judicial killing in 2005 of accused gangster Sohrabuddin Sheikh and his wife Kauser Bi in western Gujarat state, where Modi has been chief minister since 2001.
Shah, then Gujarat home minister, has been charged with being a co-conspirator in what federal investigators claim was a staged shootout to eliminate Sheikh, who was part of an extortion racket.
Gujarat police claimed Sheikh was a "terrorist" plotting to kill Modi.
In 2010, India's federal police charged Shah with murder, extortion, destruction of evidence and criminal conspiracy. He insisted he was innocent, but immediately resigned.
In a country where allegations against politicians are commonplace and police are widely viewed as corrupt, Modi weathered the storm by defending Shah as the victim of a conspiracy.
Convictions in India, especially of politicians, usually take years if not decades to secure in the log-jammed court system.
Amid a BJP election publicity blitz portraying Modi as a corruption-free man of action, the charges against Shah have gone largely unmentioned.
Criminal or crime fighter?
Shah gained a reputation during his eight-year stint as Gujarat's home minister for a swift and often deadly crackdown on crime.
In another controversial case on his watch, four people including two teenagers were gunned down in another alleged extrajudicial killing in 2004.
In September 2013 a former top Gujarat policeman, DG Vanzara, released an explosive letter from prison accusing Shah of "dirty tactics".
He was also implicated last November in a scandal dubbed "stalkergate", in which alleged transcripts of conversations between him and policemen were released by investigative news website Gulail.
In them, Shah purportedly orders officers to trail a woman at the behest of "saheb", a Hindi term for boss, ordering them to report every movement of the young architect, particularly if and when she met any male friends.
Shah again dismissed the report as a conspiracy hatched by Congress.