Ramchandra Tiwari, head of Rasulpur police station in Bihar, where the crime took place, made the announcement on Saturday.
The victim, identified as 56-year-old Naseem Qureshi, died earlier this week after being attacked by a Hindu-radical mob for being suspected of carrying beef. According to a police statement in court, Qureshi was allegedly surrounded by more than 20 people and attacked. Police forces intervened but he died on the way to the hospital, the statement added.
Cows are considered sacred in Hinduism and the slaughter of them, along with the sale, consumption, or even possession of beef is restricted in some parts of the country.
There have been frequent attacks on those accused of killing cows for meat or leather, predominantly people from the minority Muslim population. Hardline Hindu groups have been demanding a complete ban on cow slaughter across India.
Opposition parties in India accuse the Hindu nationalist BJP government at federal and state levels of discriminating against religious minorities, especially Muslims.
International rights groups have also accused Modi’s governing party of looking the other way and sometimes enabling hate speech against Muslims.
India's Muslim population makes up 14 percent of the country's 1.4 billion people but is still numerous enough to be the second-largest Muslim population of any nation.