The police constitute a central institution in crime prevention and criminal justice administration in India. Their functions extend beyond maintaining law and order to include prevention of offences, registration of information, investigation of crimes, collection and preservation of evidence, protection of victims and witnesses, and assistance to courts in the administration of justice. The historical development of Indian policing is closely connected with the colonial framework established after the Revolt of 1857 and the Police Act, 1861, the influence of which continues to shape several structural and administrative features of police functioning. This paper examines the role of police in crime prevention and criminal justice administration with reference to the Bharatiya Nagarik Suraksha Sanhita, 2023, constitutional safeguards, and leading judicial precedents. It analyses the preventive and investigative responsibilities of the police, including registration of information relating to cognizable offences, use of electronic means, search and seizure, forensic evidence, and submission of final reports before competent courts. The paper also discusses the duty of police to protect the rights and dignity of accused persons, victims, witnesses, women, children, and other vulnerable groups. The study further evaluates the growing use of technology in modern policing, including artificial intelligence, CCTV footage, digital forensics, online tracking, cryptocurrency investigation, and data analysis. At the same time, it highlights major challenges such as political interference, shortage of personnel, inadequate training, insufficient infrastructure, and low morale. The paper concludes that effective policing requires a careful balance between crime control and constitutional rights. Police reform, specialised training, technological modernisation, judicial oversight, institutional accountability, and a human-rights-oriented approach are essential for building a professional, transparent, and trustworthy police administration in India.