Inspector Subodh Kumar Singh died when the mob, throwing stones, took on the police.
Indian Police Service Association on Tuesday demanded stern punishment for the people responsible for the death of Uttar Pradesh Police Inspector Subodh Kumar Singh.
The IPS Association recognised the risks police officers take in the wake of disruptive mob mobilisations.
"We condemn the lethal attack on UP police Inspector Subodh Singh, recognise his bravery and risks police officers are exposed to because of disruptive mob mobilisations," read a tweet on the Association's official Twitter handle.
"We demand the strongest action against perpetrators and instigators," it added.
Police inspector Subodh Kumar Singh and a few other policemen were trying to control the mob when they were outnumbered and the situation went out of control. Mr Singh was hit with a stone by the mob, which went on to chase his SUV, corner it in the fields and shoot him dead.
He was the Investigating officer of the Akhlaq lynching case.
Chief Minister Yogi Adityanath has declared Rs 40 lakh for Mr Singh's family, Rs. 10 lakh for his parents and a government job for a family member.
The officer's sister said he had been killed because he had investigated the mob lynching of a Muslim man Mohammad Akhlaq in Dadri in 2015.