In February 2008, Roy was transferred from superintendent of police of Sherpur District to the Criminal Investigation Department with the rank of special superintendent of police.[6] He was transferred from special superintendent of police of the Criminal Investigation Department in Rajshahi District in August 2008 to superintendent of police in Chandpur District.[7] In May 2009, Roy was the superintendent of police in Chandpur District[8] when 30 homes were burned down in an arson attack over char land.[9]
Roy provided security to a rally of the Bangladesh Nationalist Party in 2010 as they attempted to lay siege to the Bangladesh Election Commission office over the by-election in Bhola District.[10] In 2011, Roy was elected assistant publicity and publication secretary of the Bangladesh Police Service Association.[11]
In April 2012, police officers under Roy, who was then the deputy commissioner (Ramna Zone) of Dhaka Metropolitan Police,[12] assaulted two journalists, from Samakal and Kaler Kantho, at the University of Dhaka.[13] Roy assured the journalists that action would be taken against the involved police officers.[13]
Roy led raids to arrest foreigners illegally staying in Bangladesh in November and detained 31 people from different African nations.[14] On 3 December 2014, Roy, then deputy commissioner of the Detective Branch (South) arrested three Rohingya linked with Jama'atul Mujahideen Bangladesh and the 2014 Burdwan blast in India.[15] They were arrested after a tip off from the National Investigation Agency of India.[15] The suspects were also linked with the Rohingya Solidarity Organisation.[15] The arrest followed greater cooperation between law enforcement agencies in Bangladesh and India on counterterrorism.[15]
In April 2015, Roy was promoted from deputy commissioner to additional deputy inspector general of police.[16] He launched a new format for filing general diaries with the Dhaka Metropolitan Police.[17] He investigated the murder of Niloy Chatterjee.[18]
In 2017, Roy was the joint commissioner of crime in the Dhaka Metropolitan Police.[19] His team investigated the son of the owner of Apan Jewellers for rape at the Raintree Hotel in Dhaka.[20]
Roy spoke at the launch of JOY, a mobile application developed by Ministry of Women and Children Affairs for women to report violence against them and seek aid from law enforcement, at the Bangladesh Shishu Academy.[21] In November 2018, Roy was promoted to deputy inspector general of police.[22]
On 29 July 2020, Roy was the additional police commissioner of Dhaka Metropolitan Police of crime[24] when a bomb exploded at Pallabi Police Station under his command.[25] The bomb was hidden in a weight scale seized by the police as evidence.[25] The Islamic State claimed responsibility for the explosion which the government denied.[26][27] He praised the Bangladesh Police and the government for increasing the posts for senior officers which he said would help reduce crime in Dhaka.[28] He told the media that criminals were using face mask requirement during the COVID-19 pandemic in Bangladesh to hide their identity.[29]
On 18 July 2022, Roy was appointed the commissioner of Chattogram Metropolitan Police.[4][30] He was serving as the additional police commissioner of Dhaka Metropolitan Police.[4] He replaced Saleh Mohammad Tanvir, who was appointed director of Central Police Hospital.[4] In October, he led raids before a Bangladesh Nationalist Party rally but denied allegations that he was targeting Bangladesh Nationalist Party activists.[31][32]
Roy was sent to forced retirement after the fall of the Sheikh Hasina led Awami League government in August 2024.[33]
