The police in Delhi and Rajasthan have become the first in India to record, store, and analyse biometric data such as fingerprints and retina and iris scans of all those arrested and others accused of crimes.

Due to the limitations of forensic capabilities, the collection of DNA, likely drawn from blood samples, is yet to be rolled out, police officials said.

These biometric samples are being collected since March in compliance with the Criminal Procedure Identification Act, which was passed by Parliament in 2022 and has now come into effect on a pilot basis in Delhi and Rajasthan after three years.

The Act enables the police and Central investigating agencies to collect, store and analyse physical and biological samples.

Though the Act and its Rules do not explicitly mention the collection of DNA samples and face-matching procedures, the National Crime Records Bureau (NCRB) has informed State police officials that such measures will also be rolled out in around 1,300 locations spread across police districts, commissionerates, and Special Investigation Units at State headquarters.

The NCRB has been tasked with implementing the Act and has finalised the Standard Operating Procedure to be followed by police officials.

Such guidelines have been completed for the collection of finger-impressions, palm-prints, footprints, photographs, iris and retina scans, physical and biological samples and their analysis, and behavioural attributes including signatures, handwriting, or any other examination.

The NCRB has held meetings with forensic laboratories to finalise the DNA loci pointers to be used in DNA profiling under the Criminal Procedure (Identification) System, which it has developed.

Rajasthan Director General of Police U.R. Sahoo told The Hindu that the Act has been implemented in some police districts.

A Delhi Police official said that such data is being recorded for all accused persons, irrespective of whether they have been arrested or not.