The missing piece: Forensics in criminal investigation

As pressure mounts and caseloads snowball in police stations and labs, rapid scaling-up of forensic infrastructure carries both rewards and risks
Last Updated : 18 September 2022, 03:16 IST

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For eight long years, the murder of a 22-year-old man in southwest Delhi remained unsolved. Despite suspicions that Ravi Kumar, the victim, had been killed by his bride and her lover, police had not found any clues, including the body, to make their case.

After encountering multiple dead ends, the police consulted forensic experts as the last resort in 2017. The experts, using brain electrical oscillation signature profiling and video surveillance, finally pieced the puzzle together. Ravi’s body was found and exhumed through leads obtained after forensic psychologists interviewed the suspects.

This case is one of many in which the use of forensic techniques has been central to building strong cases, particularly in heinous crimes like homicide, sexual assault and burglary. In addition to analysing fingerprints, biological matter (blood, skin, hair, nails) and ballistics, forensic science provides the tools to examine documents, mobile phones, computers and audio-video footage.

In Ravi Kumar’s case, forensic psychologists were only consulted at the last stage. According to Mumbai-based forensic psychologist Krupa Nishar, “It has become a last-ditch attempt, this should not be the case.” This is also true for other forms of forensic analysis, which examine even biological and digital evidence.

High caseload, outdated equipment, dearth of experts and lacunae in police training and implementation make forensic analysis a resource that is rarely available or sparingly used.

As a result, lack of evidence is a primary factor which has led to India’s abysmal conviction rate of 35.5 per cent for offences against the human body, including murder, sexual assault, kidnapping and human trafficking, according to 2021 data from the National Crime Records Bureau.

Police confirm that having no evidence is a major roadblock in the progress of many cases. In 2021, over 6 lakh cases were deemed ‘true’ by the police under various Indian Penal Code (IPC) sections and local laws, but could not be proved due to insufficient evidence.

Union Home Minister Amit Shah recently announced that forensic investigation would be made mandatory for all offences with a punishment of over six years. Shah set the target conviction rate at an ambitious 90 per cent. The current conviction rate for offences under IPC sections is only 57 per cent.

Currently, only 10 per cent to 12 per cent of cases are referred to forensic science laboratories (FSLs) in India, yet they are already weighed down with pending cases. While India has about 120 government forensic laboratories at state and district levels, and about 5,000 experts working to analyse forensic evidence, the quantum of demand is far greater. A study shows that if all cognisable offences are referred to FSLs, the pendency of cases would increase eightfold.

In Karnataka, the FSLs are involved in about 18 per cent of all cases registered annually.

“Even labs in Mumbai and Delhi are struggling with high caseloads. When they have sufficient equipment, they do not have experts and when they do have experts, they lack the equipment,” Nishar says.

Over half of the cases referred to forensic laboratories in India are still pending. Some have been awaiting DNA and toxicology processing for about two years, according to a 2021 study.

Inertia in adopting modern, state-of-the-art forensic techniques in criminal investigation leaves India far behind global standards. In most developed countries, there are 20 to 50 forensic scientists per 1 lakh people. India has 0.33 forensic scientists per 1 lakh people. There are only about 5,000 forensic professionals working in labs across the country. Additionally, 42 per cent of police said that forensic technology is never available at their station, according to a 2019 report.

“India's position is pathetic and dismal. Despite repeated reminders from the Supreme Court, probe agencies seldom follow rules,” says K B K Swamy, an advocate who specialises in criminal prosecution.


A criminal investigation begins when a heinous crime is reported and police visit the scene. However, interference can contaminate evidence at this level only.

While securing the crime scene is the most vital first step, there are several competing priorities that often take precedence. “As police officers, there are a number of angles to consider. When we receive reports of a heinous crime, our first priority is to maintain law and order. The second is to pursue suspects who may be on the run,” says A Subramanyeswara Rao, Additional Commissioner of Police (East), Bengaluru.

In such cases, evidence collection ends up on the sidelines.

Jurisdictional inspectors have the responsibility to identify relevant evidence at the crime scene, mark it with numbers and collect the evidence methodically. Blood swabs go in saline solution, personal belongings are collected with gloves and sealed in plastic bags, paper is collected in paper bags and footprints and fingerprints are lifted from surfaces at the crime scene. Both biological and non-biological materials have specific protocols for identification and collection. However, practically, these standards are erratically followed due to a range of factors such as staff shortage, long work hours and administrative duties.

Overworked and tasked with a range of responsibilities, the inclination of police personnel to follow standard procedure is inconsistent.

A majority – about 87 per cent – work for over eight hours a day, and out of this, 24 per cent work more than 16 hours in a day. They are forced to work longer hours due to staff shortages, with only 77 per cent of sanctioned positions being filled.

“There are about 120 cases that I have to oversee right now,” said an inspector from Bengaluru. “Apart from investigative work, there is administrative work, court hearings and other law and order duties that we must perform. It is not as though we do not wish to give a case the time it needs,” he adds.

The caseload is even higher in some states, like Gujarat, where each officer handles 167 cases, and Odisha where this number is 155.

Research shows that high caseloads do not only correlate to low conviction rates and court delays, but also to substandard evidence collection and analysis.

Two years ago, in a high-profile narcotics investigation, hair follicle samples were sent by Karnataka police to the Central Forensics Science Laboratory in Hyderabad. However, the samples were returned due to improper packing and collection.

Such technical lapses have occurred in a number of cases. Fingerprint collection is also a major area of concern. “When fingerprint samples are collected from suspects using ink on paper, they can be corrupted in the process of collection, or while packing and sealing. The ink can get smudged, or the sample may not be stored properly, leading to its disintegration,” says Shreya Rastogi, an advocate who leads the forensics division at Project 39 A, National Law University, Delhi. When these samples are compared to partial prints taken from surfaces at the crime scene, they might not suffice for an accurate analysis. The collection and storing of biological material is even more difficult as it is prone to decay.


At the core of mishandling evidence and not giving due importance to scientific methods of criminal investigation is a serious lack of specialised training.

While police receive training at the academy, this encompasses a multitude of subjects including policing, criminal law, weapons training, media etiquette and physical training. A 2017 report from the Comptroller Auditor General revealed that police training academies had a large number of vacancies for trainers in interrogation and a dearth of equipment in forensic sciences and cybercrime.

In fact, researchers found that one in three civil police personnel in India never received training in forensic technology.

Experts emphasise that it is essential to ensure that personnel with a specialisation in forensic science are present at every stage of the criminal investigation process. In line with this objective, earlier this year, Karnataka was the first state to introduce ‘scene-of-crime officers’.

“The scene-of-crime officers are either graduates or post graduates in forensic science. 206 positions were sanctioned, and we have recruited candidates to fill all positions. 43 candidates have already been appointed and document verification is underway for remaining candidates. After training, they will be stationed in different districts,” says Dharmender Kumar Meena, director of the Karnataka Forensic State Laboratory.

150 scientific officers have also been hired in the past two years in Karnataka.

However, such efforts have not been replicated across all states. Even in Karnataka, the lack of manpower had been a persisting issue until 2019, when 60 per cent of state FSL positions were vacant. This was exacerbated by infrastructural and funding issues. Such problems led to a serious pendency of cases from which we have still not recovered.

Capacity building is welcome but is gravely insufficient when there is no will to use facilities that are available.

Last month, in a case of sexual assault and murder, tried by the Madhya Pradesh High Court, DNA samples had been collected by the police. Upon consultation with a scientific officer from the forensic science lab, it was recommended that these samples be sent for DNA profiling. However, the investigating officer did not follow through, and of which the suspect could not be convicted.

Condemning the negligence of the police, in their ruling, the court states that forensic analysis “would have made a watertight prosecution case but it was also not done, may be purposefully or negligently.” The court directed the state to initiate an inquiry and “proceed against the responsible officers who are guilty of dereliction of their duties in accordance with law…”

Prejudice and torture

“They had no case or evidence against me, but I had to confess to the crime because they tortured me,” says Abdul Wahid Sheikh, who was acquitted due to lack of evidence after spending nine years in prison. He was one of 13 suspects in the 2006 Mumbai train bombing case and was picked up for questioning and then imprisoned for almost a decade.

Sheikh explains that his incarceration happened because a false narrative was concocted and witnesses threatened. The case against Sheikh fell apart in court six years later when a witness confessed in court that his statement had been given under police pressure.

“In India, instead of looking at clues and evidence to find suspects, the police zeroes in on a suspect and reverse engineers a case by coercing confessions and witness statements against them,” he says.

In the absence of forensic expertise at the point of investigation, “Police use emotional and physical stress to interrogate suspects. Under pressure to present results, they resort to third-degree torture,” says Nishar.

The departure from scientific methods of analysis and standard operating procedure means that the police’s pre-existing biases against religious minorities and deprived castes come to the fore during investigation.

A 2019 report reveals that one in two police personnel believe that Muslims are naturally prone to crime, and one in three believe the same of Dalits. A scientific temper in the investigation process– one that looks at evidence and derives conclusions rather than vice versa – is the need of the hour. Forensic science, in this context, calls for the prioritisation and systematic processing of evidence.

At present, the police continue to rely on witness statements and confessions in presenting their cases before courts. “In most cases, witnesses turn hostile, influenced by threats, money and other factors. Secondly, trial takes a long time. Witnesses may also not remember their accounts, and give different versions of their statement in court,” says A Subramanyeswara Rao, Additional Commissioner of Police, East Zone, Bengaluru.

A thin line

While reliance on forensic methodologies can improve objectivity, it is vital to be cognisant that even these are not exempt from potential misuse. On the road to achieving a 90 per cent conviction rate in the country, mounting pressure poses a real risk of even forensic evidence being misused and tampered with to construct and support convenient narratives.

“The presence of forensic evidence can cause procedural lapses to be overlooked even in court. It has a cleansing power due to the shield of objectivity that it is associated with. Most forensic labs are not independent and are not free of police influence. Evidence can be manufactured to tell a certain story. This can cause grave injustices,” Rastogi says.

The potential for misuse of evidence is already high. With the introduction of the Criminal Procedure (Identification) Act, 2022, this risk will only be magnified. Among other powers, the Act makes provisions for the handling of evidence by police personnel in constabulary positions, who may not have sufficient training.

The Act also allows for the collection, recording and storage of ‘measurements’ which include finger-impressions, “physical, biological samples and their analysis, behavioural attributes including signatures.” The term ‘biological samples’ has not been defined. Such vague definitions are replete in the Act, widening the ambit of police power.

Law enforcement personnel, on receiving permission from the magistrate, are also authorised to collect biological samples from ‘any person’ – which includes convicts, detainees, suspects or any person who the police deem may help the investigation.

The data collected could be stored in databases managed by the National Crime Records Bureau, Union or state governments. “In the US, it has been proven that such databases have led to increasing surveillance and policing of vulnerable communities. Beyond privacy concerns, databasing can increase police profiling and disproportionately affect deprived castes and minorities,” Rastogi concludes.

The path towards improving criminal investigation through forensics is ridden with both risks and rewards. As India toes this line, experts insist that robust accountability measures, clarity in definitions and limitations to power are as integral as the modernisation and adoption of forensic sciences.

Published 17 September 2022, 17:58 IST

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