FORENSIC BIOLOGICAL EXAMINATION

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Forensic biological examination is a technical field of expertise covering the scientific analysis of biological material in criminal investigations, suspicious death cases, allegations of sexual assault, and parentage (lineage) disputes.
As a forensic medicine specialist, scientific and reasoned expert opinions are provided regarding DNA analysis, evaluation of biological samples, and the interpretation of laboratory results within a legal framework. 

Forensic biology involves the evaluation of human-derived biological materials (blood, semen, saliva, hair, tissue, etc.) in criminal and legal processes. 

The fundamental questions in judicial processes are:

• Does the obtained biological sample belong to a human?

• To whom does the DNA profile belong?

• Is the sample linked to the incident?

• Is there a possibility of contamination?

• How should a mixed DNA profile be interpreted?

In these evaluations;

• Council of Forensic Medicine practices,

• Supreme Court precedents,

• International forensic genetic standards
  are taken as the basis.

• Bloodstain pattern analysis

• Semen and vaginal swabs

• Saliva and epithelial cells

The presence, source, and relationship of the biological sample to the incident are evaluated .

• STR profiling

• Comparative DNA analysis

• Interpretation of mixed profiles

• Father-child (parentage) analysis

DNA matching is evaluated only within the framework of statistical probability; the concept of "absolute certainty" is not scientifically accurate .

• Presence of root and DNA suitability

• Identification in tissue samples

• Biological matching in fragmented remains

Identification is of critical importance, especially in burned or advanced-stage decomposed corpses .

In allegations of sexual assault, the timely and correct collection of biological samples is of great importance.

Within the scope of the evaluation, the following are analyzed based on scientific criteria: 

• Presence of semen and DNA profile

• Epithelial transfer

• Correlation with traumatic findings

• Time factor

DNA analysis has a high accuracy rate in parentage disputes. 

However, the evaluation is conducted by taking the following elements into account: 

• Statistical probability ratio (Likelihood Ratio)
   
• Probability of mutation
   
• Sample reliability
   
• Chain of custody 

Scientific evaluation includes the following stages: 

1. Examination of the source of the sample and collection conditions
    
2. Evaluation of the chain of custody process
    
3. Examination of the laboratory analysis method
    
4. Statistical analysis of DNA profile comparison
    
5. Technical interpretation of mixed profiles
    
6. Scientific explanation of the probability ratio
    
7. Preparation of a reasoned expert report
    

A laboratory result alone is not sufficient; it must be evaluated together with incident data and other evidence. 

One of the most common problems in practice is mixed DNA profiles. In such files, the following are analyzed based on scientific criteria: 

• How many people the genetic material belongs to

• Who the main contributor is

• The possibility of secondary transfer

• Risk of contamination Kaç kişiye ait genetik materyal bulunduğu
   

Incorrectly interpreted DNA reports can lead to the risk of erroneous convictions or unjust acquittals.

• Sexual assault files

• Suspicious death cases

• Identification files

• Parentage (paternity) lawsuits

• Fragmented corpse examinations

• Criminal files requiring biological evidence evaluation

• etc

Is a DNA match definitive evidence? 

DNA analysis is based on statistical probability; it requires scientific interpretation. 

How is a mixed DNA profile evaluated?
Contribution rates and statistical calculation methods are used. 

Is sample contamination possible?
A definitive evaluation cannot be made without examining proper storage and analysis processes. 

What is secondary DNA transfer?
It is the transfer of a person's DNA via a third surface without direct contact.

• Technical and statistical interpretation of laboratory data

• Analysis of the chain of custody process

• Scientific explanation of DNA matching

• Reasoned reporting suitable for judicial review

• Impartial and objective approach Laboratuvar verilerinin teknik ve istatistiksel yorumu
   

Forensic biological examination is not merely the reading of a laboratory output, but a technical field of expertise requiring scientific analysis and statistical interpretation. 

You can request a scientific preliminary evaluation regarding files involving DNA, biological evidence, or parentage, and contact us for a detailed expert opinion.
For lawyers and individual applications, a review is conducted over the file.