From arresting three Jawaharlal Nehru University (JNU) students on charges of sedition to the booking of several Aam Aadmi Party (AAP) MLAs, 2016 saw Delhi Police battling a series of controversies even as it cracked a number of high-profile cases, nabbed wanted terrorists and busted an espionage ring involving a Pakistan High Commission staffer.
Crime against women continued to rise and a number of brutal rape and assault cases kept the police on its toes though it managed to solve some of them in quick time.
In June, a multi-city kidney racket involving doctors and touts was busted by Delhi Police, while it arrested Khalistan Liberation Front chief Harminder Singh Mintoo who had escaped from Nabha jail. A number of persons suspected to have links with ISIS and al Qaeda were also caught in the course of the year.
Women safety in the national capital continued to be a cause of concern with 1,981 cases of rape being reported till November 30 even as police launched a number of initiatives to contain crime against women.
The brutal stabbing of a 21-year-old girl in Burari in broad daylight in September by a man who was allegedly stalking her for several months, and the videos of the shocking incident left people horrified.
In February, the arrest of JNU Students Union president Kanhaiya Kumar and two others on charges of sedition for allegedly organising an event against hanging of Parliament attack convict Afzal Guru, triggered a huge controversy with Opposition political parties slamming police for "working at the behest of ruling BJP".
The arrest of Kumar catapulted him to national fame and resulted in students protests across the country. The arrests also led to a nationwide debate on nationalism. Police had also come under severe criticism following attacks on journalists and students and teachers of JNU at the Patiala House court by some lawyers just before Kanhaiya was to be produced.
In October, JNU student Najeeb Ahmed went missing, a day after he was allegedly involved in a brawl with some students including ABVP activists, leading to an agitation with students alleging police inaction in tracing him.
The uneasy relationship between the AAP government and Delhi Police continued this year as police arrested nine AAP MLAs, drawing angry reaction from the party with Chief Minister Arvind Kejriwal alleging the law enforcing agency was acting at the behest of Prime Minister Narendra Modi.
The MLAs arrested are Dinesh Mohaniya, Prakash Karwal, Gulab Singh, Amanatullah Khan, Somnath Bharti, Rituraj Govind, Naresh Balyan, Sharad Chauhan and Jagdeep Singh and the charges ranged from rioting, outraging the modesty of woman, sexual harassment, criminal intimidation and assault.
Sandeep Kumar, who was sacked as Cabinet Minister over an "objectionable" CD, was arrested on rape charges on the complaint of the woman who purportedly figured in the CD.
The Anti-Corruption headed by Mukesh Kumar Meena, was also involved in a tussle with the AAP dispensation over registration of cases and questioning of AAP ministers and MLAs, including deputy chief minister Manish Sisodia, Kapil Mishra, Gopal Rai, Amanatullah Khan.
The brutal killing of a 23-year-old Congolese national by three youths following a brawl over hiring an auto-rickshaw in south Delhi in May made national headlines as the government rushed to assure the African community in India of their safety.
Delhi Police's Special Cell continued to clamp down on terror activities with the arrest of six people for suspected links with al Qaeda and ISIS.
The year ended with them nabbing Mintoo, who had escaped from Nabha jail, from Nizamuddin railway station here.
In October, the Crime Branch also busted an espionage ring with the arrest of four people who were allegedly sharing sensitive defence documents and deployment details of BSF along the Indo-Pak border with a Pakistan High Commission staffer.
The staffer Mehmood Akhtar was later declared persona non-grata by the government and he had to leave the country.
Following the demonetisation of high-value currencies, police raided various areas across the city and recovered over Rs 17 crore in illegal cash.
The year ended with a 20-year-old girl, who was on a job hunt, allegedly being raped in a car in South Delhi's Moti Bagh area, a grim throwback to the horrific Delhi gangrape of a para-medic student in a moving bus four years ago.
The alleged suicides by former Director General Corporate Affairs B K Bansal and his son in September, two months after his wife and daughter committed suicide, allegedly due to harassment by CBI, not only drew criticism for the premier investigating agency but also for police as it didn't register any case despite the presence of purported suicide notes of Bansal and his son.
The contentious case of Sunanda Pushkar didn't see any headway for the second consecutive year even as police accepted that her death was not natural and questioned her husband Shashi Tharoor and Pakistani journalist Mehr Tarar in February.
Some of the other developments in the case included the formation of a medical board to study the FBI report, sending reminders to Canada to send details of deleted chats from Tharoor and Sunanda's Blackberry phones, and Enforcement Directorate being requested to investigate the financial irregularities related to now-defunct Kochi IPL franchise.
Some of the high-profile cases being investigated by Delhi Police included hacking of Twitter and email accounts of Congress vice-president Rahul Gandhi and missing files concerning Ishrat Jahan encounter from MHA.
The Crime Branch cracked down on the notorious red light G B Road in the heart of the city in August dismantling a vast human trafficking and prostitution racket, arresting the kingpin couple and their several accomplices.
The suicide by an ex-serviceman close to Ministry of Defence building over the OROP issue kept police busy with many politicians raising the issue and slamming Modi government.
As many as 3,400 personnel of paramilitary and Delhi Police were deployed at banks and ATMs across the national capital after serpentine queues led to law-and-order problem in some areas.
In the new year, police envisages to modernise its operations and reduce the burden on its more than 80,000 personnel by mulling over the possibility of introducing eight-hour shifts on the lines of its Mumbai counterpart.
Delhi Police will also be setting up a separate control room for handling calls on phone number 112, which will be India's equivalent of 911 of the US' all-in-one emergency services, that will be rolled out from January 1 and the closure of 100 that is the go-to solution for people in distress.