1958–1984

Gill joined the Indian Police Service in 1958 and was assigned to the Assam and Meghalaya states in northeast India.^[4][11]

In the early 1980s, Gill served as Inspector General of Police in Assam. Vinayak Ganapathy, writing for rediff.com in 2003, noted Gill's no-nonsense style of functioning, which earned him the sobriquet 'supercop' in Punjab, made him "unpopular" among influential sections of the population in Assam and called him "a controversial figure".^[12] While Director General of police in Assam, Gill was charged with kicking a demonstrator to death, but was acquitted by the Delhi High Court.^[13][14] Gill lived in the northeast region of India for 28 years, returning to his home state of Punjab in 1984.^[15]

1984–1995

He has been called a 'supercop',^{[16][17][18][19]} for his work in Punjab, where he was the Director General of Police^{[2][3][4][16]} from 1988 to 1990 and then again from 1991 until his retirement from the Indian Police Service in 1995.^[20]

During this era when Sikh extremists in the Khalistan movement were active in Punjab, there were reports of human rights violations in the Punjab region. Amnesty International reported that, from 1983 to 1994, armed groups "struggling" to form an independent Sikh state, assassinating perpetrators of the 1984 Sikh pogroms or Congress Party members, and taking hostages. It further reported that the police responded with a crackdown, "illegally detaining, torturing and killing hundreds of young men".^[21] Human Rights Watch (HRW) reported that from the 1980s Sikh separatists were guilty of targeted assassinations and attacks upon Hindu minorities in the Punjab state. HRW also reported that the government response resulted in further serious "human rights violations against tens of thousands".^[22][23] HRW report in 1991 described the security forces using "increasingly brutal methods to stem the militant movement, resulting in widespread human rights violations." Thousands of civilians and suspected militants were summarily executed in "staged" encounter killings. Many "disappeared" while in police custody and thousands were detained without trial and subjected to torture.^[14] The post-1991 period coincides with Gill's second tenure as Director General of Punjab police. It is this period that witnessed the most serious escalation of violence.

In May 1988, he commanded Operation Black Thunder to flush out militants hiding in the Golden Temple. Compared to Operation Blue Star, little damage was inflicted on the Golden Temple.^[24] In what was reported as a successful operation, around 67 Sikhs surrendered and 4 were killed in the encounter. Gill stated that he did not want to repeat the mistakes made by Indian army during Operation Blue Star.^[25] In contrast to prior operations, minimum force was used under full public scrutiny.^[26][27]

1991 saw the peak of violence in Punjab, with more than 5000 reported killed. In 1992, the Indian government, intent on retaking Punjab from terrorism, appointed Gill as Chief of Police in Punjab. The police and army instituted a crackdown, and in 1993 the reported death toll was less than 500. In 1993, The New York Times reported, the people of Punjab no longer feared the Sikh rebels or gangs, but instead feared the army and police.^[28] Patricia Gossman describes Gill as having a goal to eliminate, not merely arrest, militant Sikh leaders and members. KPS Gill also expanded a bounty system of rewards for police who killed known militants – a practice that encouraged the police to resort to extrajudicial executions and disappearances.^[29] The police were awarded financially for killing militants. India's central government created a special fund to finance Punjab's death squads, to pay the network of informants who provided information about militants and those suspected of supporting militants, and to reward police who captured and killed them.^[30] The reward was about ₹50,000 ($1,670). In an article in India Today on 15 October 1992 it was written that the rush of claiming cash rewards is turning police into mercenaries. Besides the rewards for killing militants (annual outlay for the purpose: ₹1.13 crore [$338,000]), the department gives 'unannounced rewards' for killing unlisted militants.^[31]

Jaswant Singh Khalra was a human rights activist who was taken into custody by Punjab Police on 6 September 1995.^[5] Human Rights Watch reported that an 11 September 1995 writ of habeas corpus from the Supreme Court was presented to Gill,^[32] and officials denied that police had detained him.^[5] (2005 testimony by Special Police Officer Kuldeep Singh indicated that Gill later visited Khalra in October 1995, a few days before Khalra was killed.^[6][33])

Under Gill the scope of tracking down and arresting militants went beyond Punjab to other parts of India. "There were several reports during 1993 that Punjab police hit teams were pursuing alleged Sikh militants in other parts of India. On 17 May, one such team raided an apartment in Calcutta looking for alleged militant Lakshmi Singh. According to neighbours, Punjab police commandos broke into the apartment early that morning, shot Singh and his wife in their bedroom, then fled with the bodies. The government of West Bengal lodged a protest with the Punjab government, but no disciplinary action was reported against the police commandos".^[34]

1995–1999

Gill founded the Institute for Conflict Management (ICM)^[35] and was its first president.^[36]

Gill began advising governments on counter-terrorism matters.^[4]

In 1997, the Chief minister of Assam state, Prafulla Kumar Mahanta, requested his services as security advisor. However, since the sexual harassment case against him was pending he was not able to take this appointment.^[20]

In 1999, Delhi Police arrested Richhpal Singh, who was allegedly a Babbar Khalsa suicide bomber on a mission to assassinate Gill. He arrived in Delhi from Pakistan on an Afghan passport. Two kilograms of the explosive RDX, four detonators, and some 'live wire'^{[clarification needed]} were recovered from him.^[37] In an interview after this incident, Gill claimed that he had been a target of four or five such assassination attempts by Babbar Khalsa and other Sikh militant groups. Gill stated that he was not afraid.^[38]

2000–2004

In 2000 the government of Sri Lanka sought his expertise as an anti-terrorism expert to help them draw a comprehensive counter-terrorism strategy against Liberation Tigers of Tamil Eelam^[39] He was approached by Lakshman Kadirgamar who was the foreign minister of Sri Lanka^[40] After the defeat of Liberation Tigers of Tamil Eelam the similarity in the tactics used by Sri Lanka with the tactics used by Gill in Punjab was noted in an article published in India Today^[41]

Gill was appointed security adviser to the state of Gujarat after 2002 Gujarat violence.^[4] Gujarat Chief minister Narendra Modi, commenting on his appointment, stated, "It is good to have an experienced person such as Gill as my security advisor. Gill had very effectively tackled the Punjab terrorism problem."^[42] He requested deployment of 1,000 extra specially-trained riot police from Punjab state to combat the violence.^[43] He was credited with controlling violence after his appointment.^{[44][45][46][47]} He arrived in Gujarat on 3 May 2002^[48] He subsequently blamed a 'small group' of people for the Gujarat riots.^[49]

In April 2003, there was a report that Gill was being considered for the position of governor of Assam. The Northeast Study Group, of which Gill is a member, had advised against assigning a state's previous security personnel to a state as governor. The Chief minister of Assam agreed.^[12]

Martin Regg Cohn argued in a Toronto Star editorial that policies followed in Punjab by Gill should be utilised in fighting the Taliban in Afghanistan.^[50] An academic paper, The Gill Doctrine: A Model for 21st Century Counterterrorism?, analysing his tactics in the successful fight against the Punjab insurgency was presented at the annual meeting of American Political Science Association on 30 August 2007.^[51]

2005–2009

The government of Chhattisgarh state in India appointed him a security adviser to help control Naxalites in 2006.^[52] After an attack by Naxalites killed 55 policemen in 2007 Gill commented that the issue was one of underdevelopment in police forces. The state policy was to leave these tribal areas alone and that gave Naxalites a base. There used to be just 3,000 police for an area the size of Switzerland. That is now changing but it will take time. But yes, it is a winnable war.^[53]

In March 2008, India's hockey team failed to qualify for the Olympics for the first time since the team's debut in 1928. Narender Batra, one of 11 IHF vice-presidents, on resigning his position over the failure to qualify,^[54] accused Gill of "autocratic functioning", and called on the entire IHF staff to step down.^[55][56] Gill responded that the critics were professional mourners who were proud to run down the establishment,^[55] and stated he would respond to these things at a later stage. They did not have an instant coffee machine that they can get results instantly.^{[57] [58]}

Alok Sinha, writing for India Times, noted that the top two executives, Gill and the Secretary-General, did not even talk to one another.^[59] There were rumours that the secretary general of the IHF, leader of the anti-Gill faction, would also resign.^[60]

Less than a month after the qualification failure, in April 2008, Aaj Tak Television reported that it had caught the Secretary-General of the IHF taking a bribe on camera to choose a player in a sting.^[61][62] There were renewed calls for Gill to resign.^[63][64]

After the allegations of corruption, the Indian Olympic Association (IOA) suspended the IHF indefinitely on 28 April 2008.^[65] IOA president Suresh Kalmadi said in a press conference, "We have great respect for KPS Gill and it is not personal."^[61]

As of September 2009, Gill remained president of the Institute for Conflict Management.^[11] As of July 2009, he was also winding up the affairs of the suspended Indian Hockey Federation as it merged with its replacement, Hockey India.^[66]