How To Collect Hair Evidence in India?


According to Locard’s Exchange principle of contact by Dr. Edmond Locard “Every person who is physically involved in the crime leaves some minute trace of his or her presence and often takes something away”. This trace constitutes physical evidence of a crime scene. The admissibility of such evidence depends on its potential to support the case. Physical evidence has been broadly categorized into a) movable evidence – such as hair, fiber, bullet etc. and is there because of the culprit and victim b) fixed evidence – such as fingerprints, footprints, blood samples, etc. because of the nature of the crime.

Hair is a fiber approximately near 0.1 mm. It constitutes one of the important pieces of evidence at a crime scene. It is the outgrowth of humans and even animals. Each person has hair which differs from the composition of other hair. Since people shed hair continuously due to biological development or it may grabbed during the encounter or strike of an object. Therefore it becomes important to study the structure, character and chemical analysis to identify the perpetrator or at the most give a lead to the case.

Hair types and its importance as physical evidence

Hair is present both on humans and animals. Various tests have been laid down to distinguish between the same. Also, it seems like our full body is covered with hair. Each region like pubic hair, head, chest, armpits, legs, face, nose etc. each when microscopically tested shows from which part of the body they originate, their phase of growth, the chemical treatments are done etc.

Physical evidence such as hair is important because it is biological evidence. To simplify, it helps in establishing the scope of the crime scene by simplifying the crime scene, identifying the perpetrator, creating a link between suspects and weapon and supporting witness statements and back up circumstantial evidence.

Most Common methods/collection of hair specimen

  1. Visual collection – Many times the hair specimen is clearly visible to the naked eyes. Strong lights such as laser light or infrared light should be used to trace hair. In such cases, it needs to be carefully picked by either hand or by using a forceps. The sample needs to be placed in the paper and sealed.
  2. Tape lifting – This method is used to pick up fiber and hair both to capture both visible and not visible hair. This method includes applying tape (not too sticky) to the patch and removing it.
  3. Vacuuming – The risk of contamination makes it the least desirable process. However, this method is used in large crime scenes. It involves placing a filter at the start of the vacuum and collecting the evidence that is caught in the evidence. The process to be successful the equipment needs to cleaned before every use.
  4. Brushing, scrapping or shaking of garment – the method involves placing a large white sheet underneath and shaking the articles on top to collect hair samples.
  5. Combing and clipping – The method is used to collect loose hairs.

Collection, preservation and marking of fiber evidence. Washing other hair analysis technique

While collecting one should be cautious and follow the following steps:

  1. Not to do: To avoid contamination do not cough, sneeze, and talk while collecting the hair sample
  2. To do: Wear a cap, gloves, mask, long sleeves shirt to avoid shedding your hair on a crime scene.
  3. Taking no. of photographs of hair with and without evidence and labelling it.
  4. Using any of the common methods like tapping, combing tweezing etc. to collect the hair samples. While tweezing being extra careful not to break the hair shaft.
  5. In case the hair is attached to any object and is not easily removable then wrap the object along with hair or the area with the hair attached and seal it.
  6. In the case of rape cases, the pubic region of the known suspect should be combed in addition to collecting about 50-100 hairs of the head. It is important to follow the fiber standards i.e. it is important that appropriate and adequate samples are submitted along with it. For e.g. in case the victim was hit by a rod on a chair then along with the rod chair should also be submitted as a sample.
  7. The next step involves packaging the hair into the drug sample paper. Hairs from different locations or even different body parts of the same human should be wrapped separately since the location is crucial and the crime may involve more than one suspect.
  8. Label the container with the details like the place it is found, serial no., date and time etc. The evidence no. should be the same as the evidence no. of the photograph of that hair.

Protocol for evidence processing in the Forensic Laboratory

The examination of human hair in the forensic laboratory is conducted using light microscopy. It is a two-step process firstly, identifying the questioned hairs and second comparison of questioned hair with known hair. Hair grows from the hair centers called follicles in the body. The main ingredient of the chemical composition of hair is Keratin. Other elements include lead, iron, silicon, cholesterol, vitamins etc. These elements help in neuron activation analysis of hair.

Hair can be divided into three parts root, shaft and tip. The structure of hair has three parts firstly, the medulla secondly, the cortex and lastly, the cuticle.

Types of cases in which fibers may be of value as evidence/applications of hair analysis

  1. Assault and homicide
  2. Rape
  3. Burglary
  4. Hit and run

Is hair a reliable piece of forensic evidence?

There a no. of cases in the United States which show the carelessness of the FBI in convicting innocent persons to person relying on just the microscopial characteristics. In 1980, Santae Tribble case, a 17-year-old boy Santae Tribble was accused of robbery and was sentenced for 23 year on the ground that the head samples of the boy submitted had the same mitochondrial characteristics. It was finally in 2003 after DNA testing that he was exonerated. It was found that of the 13 strands of hair found at the crime scene none were his and rather it was of a dog and 3 other humans. When this wrong came into a big picture, the FBI and U.S. Attorney reworked on the cases in which hair analysis formed the main ground for convictions. Other cases like Jimmy Ray Bromgard and others “90 percent” were exonerated. On DNA testing it was found that they were innocent and the officials had made a mistake.

From above it can be seen that the process of microscopical comparison is a difficult one although it allows you to see 100x under the microscope of the original strand. This method has been replaced and now mitochondrial DNA testing of hair is done. Mitochondrial DNA could be found of the shaft of hair whereas nuclear DNA can be done from a live hair root where the nucleus lives. The mitochondrial DNA is resistant to damage. When the questioned hair is compared to the known hair and it is found similar it is said to have originated from that individual. If however, the hair is not similar it is not of that individual. It is advisable to collect hair samples from the suspect as quickly as possible because chances are that the accused may try to change the composition of his hair by dye, bleaching or by any other technique. If you may have noticed that even when both the hairs show the same characteristics the word used is ‘similar’ and not ‘match’ that’s because it is not a 100 percent match. It is thus important to say that ‘microscopial’ comparison is not that useful. With the advance in technology, DNA testing has opened new boundaries for crime investigation.

It is also useful for determining whether the individual was poisoned or whether he was under the influence of drugs. The history of drugs can be tracked using this single piece of evidence.

Thus, we see that hair is rather corroborative evidence and not the main evidence. If dealt with care and preserved rightly the DNA could be used to help to find the culprit and act as a catalyst to the whole crime investigating process.

This Article is Authored by Aarcha Gupta, 4th Year B.A.LL.B Student at Symbiosis Law School, Noida.

Also Read – What Evidence Should Be Collected First at A Crime Scene?

Law Corner

Leave a Comment