What has dismayed liberal Hindus — and religious minorities, who still see beef more as dinner than deity — is not just the brutal way Akhlaq was dragged from his bed and beaten to death with bricks by his long-time neighbours, after loudspeakers from a Hindu temple were used to broadcast rumours he had butchered a cow.
What has been most unnerving is what has been said — and not said — about the killing at the highest echelons of Mr Modi's Hindu nationalist Bharatiya Janata Party government. The BJP's ideological parent, the rightwing Rashtriya Swayamsewak Sangh, recently likened the slaughter of a cow to the rape of a Hindu girl.
"The Dadri incident is a chilling turning point in our politics," Shekhar Gupta, a former newspaper editor, wrote in the Business Standard. "It marks the rise of Hindu supremacist mob militancy that the BJP won't unequivocally disown or condemn."
India's voluble culture minister, Mahesh Sharma — also the MP for the area — has described the killing as "an unfortunate accident" and "misunderstanding".
Tarun Vijay, a BJP MP and a member of the party's national executive, elaborated in the Indian Express: "Lynching a person merely on suspicion is absolutely wrong," he wrote — the inference seemingly that if there was irrefutable proof Akhlaq had butchered a cow, his slaughter might be justified.
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The Uttar Pradesh police investigating Akhlaq's murder may have had the same thing in mind. They took samples of the meat stored in the victim's family fridge for "forensic tests" to assess whether or not it was beef, which many Hindu extremists believe should be a mitigating factor for the murderers.
Slaughtering cows is banned in many parts of India. But local BJP leaders commenting on the killing in Dadri say beef-eating is a "provocation" that would naturally prompt a forceful reaction from devout Hindus — akin to the "blame the victim" rhetoric often used for women who have been raped.
India's enfeebled opposition Congress party has hardly taken a stand either. While Rahul Gandhi has criticised "the politics of hate", top Congress leaders declared they supported a national ban on cow slaughter, heedless of the millions who regularly consume beef.
And Mr Modi? India's most masterful political communicator — who as a candidate emotionally denounced what he described as growing violence against cows — has been stubbornly silent. Some see his silence as indifference. Others believe it reflects his tacit support for the politics of hatred and fear being stoked by so many in his party.
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"The blame for this has to fall entirely on Modi," wrote Pratap Bhanu Mehta, director of the Centre for Policy Research. "This government has set a tone that is threatening, mean-spirited and inimical to freedom."
During India's 1940s-era constitutional debates, conservative Hindus had argued for a ban on cow slaughter to be included as one of the constitution's fundamental rights — which would have put protection of cows on par with guarantees such as the human right to life and equality. At the time, that proposal was rejected. Sixty-five years later, that appears to be India's new reality.