But as luck would have it, when mastermind Jagtar Singh Tara was tracked to a hideout in south Delhi, he was unarmed -- save a cyanide capsule that was hidden in his turban.
"We were half expecting the men inside to be sitting with Kalashnikov rifles, ready to fire. Instead, to our surprise and relief, we found a tall turbaned Sikh youngster sprawled leisurely in an executive chair," Kumar told IANS in an interview.
"Another Sikh, but without a turban, was also seated there, in a relaxed mode. We overpowered them in no time."
The man in turban admitted that he was indeed Tara. This was in September 1995, barely weeks after Beant Singh's assassination in Chandigarh by a suicide bomber shocked the nation.
Beant Singh became chief minister at a time when the Khalistan campaign was at its bloody peak in Punjab. Soon after he took charge of the state, security forces ended the decade-long saga of violence.
Kumar -- then with the Central Bureau of Investigation -- recalled those terse moments in an interview with IANS. "Jagtar Singh Tara's arrest was one of the most risky operations I did."
Beant Singh, the chief minister from 1992 to 1995, was killed by the Babbar Khalsa International (BKI) in a deadly suicide attack on August 31, 1995. Seventeen others were also killed.
Beant Singh had come down from his second floor office around 5.10 p.m. When he was about to get into his car in the VIP porch, the suicide bomber dressed in police uniform, Dilawar Singh, blew himself up.
Explaining the risky factors of the operation to catch Tara, Kumar said: "Tara was reported to be armed. He also had cyanide pill. We were unarmed and were four in number."
A deputy inspector general in the CBI then, Kumar knew that taking on Tara was a dangerous affair.
"My decision to come to this point without a commando unit, without weapons and bullet proof jackets, without cordoning off the entire area, without taking some local residents into confidence, could all backfire, literally, within a matter of seconds.
"All our combined heroism could blow up on our face," Kumar said.
Assisting Kumar were Assistant Sub-Inspector Anchal Singh, constables Dharambir Singh and Surinder Singh.
They suddenly barged into a shop in a small single-storey municipal market in Safdarjung Enclave in south Delhi.
That's where they found their prey. "Fortunately, there was no weapon on either of the two men."
Kumar's book 'Dial D for Don', which is basically about the Indian underworld after the 1993 serial bombings in Mumbai that was blamed on the still fugitive mobster Dawood Ibrahim or "D Company", also has a detailed description about the arrest of Tara. (IANS)