Role of Hair in Forensic Investigation

Abstract

The contribution of hair analysis in crime scene investigation is very useful and reliable for the extraction of DNA and drug analysis from the last few decades. The microscopic analysis of hair helps us to differentiate between human and animal hairs. By using different techniques, we can find out the amount and name of the specific drug that a person used it once in whole life. Immunoassay, Gas-Chromatography Mass Spectrometry and Liquid- Chromatography Mass Spectrometry are used due to highly sensitivity. In this review article, we will study about the role of hair in forensic investigation.

Keywords

GC-MS, LC-MS, Hair analysis, Drug analysis, Hair analyzed

Introduction

Mammalian hairs are types of trace evidence in course of forensic investigation. As hair is an omnipresent type of trace evidence it is found almost on every crime scene. Investigation and comparison of hair is performed by forensic experts. Testing and examination of hair sample leads us to important clues for the resolving of a crime scene. Human and animal hairs have prime importance in forensic examination for over a century. There are certain researches done on human and animal hair that are usually encountered in forensic cases. So certain guidelines are provided or recommended for hair in forensic cases. Hair is a unique type of trace evidence because of its certain characteristics such as easy to handle, easy to transfer and resilient. Hairs are used for the reconstruction of crime scene which will be helpful in solving that certain case. The successful comparison and investigation of hair is dependent on various possible factors. Some are as follows:

  • Perfect sample is representative
  • Condition of sample
  • Training and experience of the examiner.
  • Methodology and equipment must be appropriate.

Microscopic Study of Hair

Hair has major three parts that made it individual characteristic: Medulla, Cortex, Cuticle. Medulla is the innermost layer of the hair shaft. Cortex is present between the medulla and cuticle. It is the thickest part of the hair. Last one is cuticle, is the outermost part of the hair. But according to new researches, there are many other types of the hair like Amorphous medulla (has no distinct form or shape) when viewed under transmitted microscope.

Read More: Cystolithic Hair

Basic Hair Structure

Root of hair is present at the proximal end of the hair. Shaft is made up of keratin that makes the cuticle. [1]

 Human hair has non-continuous medulla whereas the animals’ hair has prominent medulla that helps us to differentiate between them after collecting it from the crime scene. On the other hand, we have a follicle at the end of the hair form where we can extract the DNA of the person. After Post-mortem, the presence of drugs and its metabolites in the hair can tell us whether a died person is smoker or non-smoker and help us to find out any poison which can cause the death of the person. (Skopp G (2010) Postmortem toxicology. Forensic Sci Med Pathol)

Shape and growth of hair

 Anagen

 This may last up 6 years. Roots are attached to the follicle for continuous growth which are used for giving the root a flame shaped appearance.

 Catagen

It starts from 2 to 3 weeks. In this phase, the hairs are continuously grow at a inhibited stage, during this stage roots acquire a elongation because the roots bulb shrinks and pushed out the hairs follicle When hair growth stops, the last phase is started.

Telogen

In this phase, the root takes on club shaped appearance. (Baumgartner AM, Jones PF, Baumgartner WA, Black CT (1979) Khajuria H, Nayak BP, Badiye A (2018)

Collection of Hair

We are randomly collected the hair from different parts of body but we are preferred the Vertex position (Back of the Head).We should cut the hair from near of the scalp surface. The location of hair should also be mentioned. ( Kintz P (2017b) Hair analysis in forensic toxicology: an updated review with a special focus on pitfalls. Curr Pharm Des). The amount of the sample is vary from test to test and depend upon from which we are going to carried out. It varies from 200mg to a single hair. Length of the hair shaft should be 3cm. Normally hairs grow to about 1cm in one month. We should collect it in a sealed plastic bag or in a aluminum foil paper.

Contamination

We should avoid contamination in the sample because it can cause problem in the result. (Cooper GA, Kronstrand R, Kintz P (2012) Society of hair testing guidelines for drug testing in hair. Forensic Sci Int 218:20–24)

          Contaminants are care product like (hair spray, hair gel, hair dye). So before starting the hair analysis we should decontamination the sample. Baumgartner and Hill resolved this problem. They said that we can remove it by washing the sample. It may be surfactants and organic solvent. Surfactants (0.1% sodium dodecyl sulphate) and Organic solvents are acetone, diethyl ether, methanol, ethanol, hexane, pentane. (Khajuria H, Nayak BP, Badiye A (2018) Toxicological hair analysis: pre-analytical, analytical and interpretive aspects. Med Sci Law 58:137–146).

Drug Analysis

Baumgartner find out the morphine sample from the hair of addicts. RIA technique is used to identify morphine drug in the hair. Detection and quantification of lorazepam in human hair by GC-MS/NCI in a case of traffic accident. (Int J Legal Med 108:265–267) Sometimes chromatographic techniques are coupled with mass spectrometry to become more efficient in term of specificity and sensitivity.

Different methods of drugs analysis

Different types of methods are used for drug analysis like Immunoassay, Gas chromatography- mass spectrometry, Liquid chromatography-mass spectrometry (Klein J, Karaskov T, Koren G (2000) Clinical applications of hair testing for drugs of abuse—the Canadian experience. Forensic Sci Int 107:281–288).

 From the drug analysis we can find out the amount and the name of the drug which is very useful for us in solving the suicidal and murder cases. BSTFA is a derivating agent commonly used in forensic hair drug analysis.( Maublanc J, Dulaurent S, Imbert L, Kintz P, Gaulier J-M (2014) Unusual pattern in hair after prazepam exposure. Toxicol Anal Clin 26:24–26.)

          It is interesting to know that the TLC can detect till 3 months from the sample (Khajuria H, Nayak BP, Badiye A (2018) Toxicological hair analysis: pre-analytical, analytical and interpretive aspects. Med Sci Law 58:137–146)

On the other hand, the cross sectional analysis of hair can tell us the drug abuse history of the person. CZE is another efficient technique that provides us the concentration of morphine and cocaine.( Wang X, Johansen SS, Nielsen MKK, Linnet K (2018).

Liquid- Chromatography Mass Spectrometry

Liquid- Chromatography Mass Spectrometry

Gas-Chromatography Mass Spectrometry

Gas –Chromatography Mass Spectrometry is used to separate a mixture of compound into individual and a detector is coupled with it. FID is not used for drug hair analysis. GS-MS is commonly used for detection of the drugs in hair. These drugs are amphetamines, benzoylecgonine, cannabinoids, cocaine, morphine. (Johansen SS, Jornil J (2009) Determination of amphetamine, methamphetamine, )

Gas-Chromatography Mass Spectrometry

Application of Hair Analysis

  1. Provide DNA evidence for criminal and paternity cases
  2. For Drug Analysis
  3. Determine the origin of person
  4. Determine if it’s come from the person or animal
  5. Used to document alcohol abuse

Conclusion

Hair is considered as very important trace evidence in forensic analysis. Hair analysis is very useful in forensic toxicology and clinical toxicology. Shape of the hair can tell us the race and origin of the person and difference in length of medulla can help us to differentiate in animal and human hair. It is also use for the detection of drug pervert.

References

  • 1. Forensic human hair examination guideline
  • 2. Skopp G (2010) Postmortem toxicology. Forensic Sci Med Pathol   6:314–325
  • 3. Baumgartner AM, Jones PF, Baumgartner WA, Black CT (1979) Radioimmunoassay of hair for determining opiate-abuse histories. J Nucl Med 20:748–752
  • 4. Khajuria H, Nayak BP, Badiye A (2018) Toxicological hair analysis: pre-analytical, analytical and interpretive aspects. Med Sci Law 58:137–146
  • 5. Kintz P (2017b) Hair analysis in forensic toxicology: an updated review with a special focus on pitfalls. Curr Pharm Des 23:5480–5486
  • 6. Kintz P (2017b) Hair analysis in forensic toxicology: an updated review with a special focus on pitfalls. Curr Pharm Des
  • 7. Cooper GA, Kronstrand R, Kintz P (2012) Society of hair testing guidelines for drug testing in hair. Forensic Sci Int 218:20–24
  • 8. Khajuria H, Nayak BP, Badiye A (2018) Toxicological hair analysis: pre-analytical, analytical and interpretive aspects. Med Sci Law 58:137–146
  • 9. Cirimele V, Kintz P, Mangin P (1996a) Detection and quantification of lorazepam in human hair by GC-MS/NCI in a case of traffic accident. Int J Legal Med 108:265–267
  • 10. Klein J, Karaskov T, Koren G (2000) Clinical applications of hair testing for drugs of abuse—the Canadian experience. Forensic Sci Int 107:281–288
  • 11.Maublanc J, Dulaurent S, Imbert L, Kintz P, Gaulier J-M (2014) Unusual pattern in hair after prazepam exposure. Toxicol Anal Clin 26:24–26
  • 12. Khajuria H, Nayak BP, Badiye A (2018) Toxicological hair analysis: pre-analytical, analytical and interpretive aspects. Med Sci Law 58:137–146
  • 13. Wang X, Johansen SS, Nielsen MKK, Linnet K (2018) Hair analysis in toxicological investigation of drug-facilitated crimes in Denmark over a 8-year period. Forensic Sci Int 285:e1–e12
  • 14. Orfanidis A, Mastrogianni O, Koukou A, Psarros G, Gika H, Theodoridis G, Raikos N (2017) A GC–MS method for the detection and quantitation of ten major drugs of abuse in human hair samples. J Chromatogr B 1047:141–150
  • 15. Johansen SS, Jornil J (2009) Determination of amphetamine, methamphetamine, MDA and MDMA in human hair by GC-EI-MS after derivatization with perfluorooctanoyl chloride. Scand J Clin Lab Invest 69:113–120

About The Author

Huzaifa Faisal is currently pursuing his graduation degree in forensic science from KFUEIT, RYK, Pakistan.