Headnotes:

Scent identification is circumstantial evidence and, as a stand-alone evidence, is incapable to prove guilt of the defendant. The scent identification must be carried out in compliance with the minimum requirements laid down by the law and relevant case law and must reflect the latest findings of scientific research into this field.

In so far as the general courts do not respect the above principles, they violate the defendant's right to a fair trial under Article 36(1) of the Charter of Fundamental Rights and Freedoms and the presumption of innocence under Article 40(2) of the Charter and Article 6(2) of the Convention for the Protection of Human Rights and Fundamental Freedoms

Summary:

I. Regional Court in Brno (hereinafter “Regional Court”) found complainants guilty of attempted robbery and damage to property of another person. The first complainant was sentenced to five years' imprisonment and the second complainant to eight years' imprisonment. The Regional Court concluded that their guilt is proven, inter alia, by their scent traces left at the crime scene and by witness statements. The High Court in Olomouc (hereinafter “High Court”) dismissed the complainants' appeals as unfounded. The Supreme Court dismissed their subsequent appeal.

The courts opined that scent identification may be used in criminal proceedings as (circumstantial) evidence. They argued that scent traces and other odour samples may, in conjunction with other evidence, establish guilt of the defendants, as long as they are secured in accordance with the requirements laid down by the law and the scent identification itself is carried out in a methodically sound and unbiased manner.

In their constitutional complaint, the complainants argued that the courts based their conviction solely or predominantly on the results of scent identification. Consequently, their guilt was not established by a direct evidence or a closed chain of circumstantial evidence but, in violation of the principles of fair trial, on a single piece of circumstantial evidence – the scent identification. In their view, the courts did not comply with the requirements laid down by the case law of the Constitutional Court.

II. The Constitutional Court stressed that presumption of innocence is one of the main tenets of fair trial in criminal matters. Along with the requirement that the guilt of the defendants must be proven in a lawful manner and beyond reasonable doubt, they form the principle in dubio pro reo. Thus, if the evidence does not establish the existence of the relevant facts beyond reasonable doubt, the defendants must be acquitted.

In the present case, scent identification was crucial in establishing the complainants' guilt. Even though the courts tried to stress that this piece of evidence is supported by other pieces of evidence, e.g. witness statements and CCTV footage showing figures bearing roughly similar physical features as the complainants, the results of the scent identification were undoubtedly the decisive piece of evidence.  

The Constitutional Court thus review if the criminal courts duly reflected the latest scientific research into the field of scent identification and complied with the requirements and principles laid down by the case law of the Constitutional Court, namely its judgement case no. IV. ÚS 1098/15. It found that the criminal courts did not comply with either of them.

It noted that it is clear from the reasoning of the Regional Court that it took into account both the relevant case law of the Constitutional Court and then-current scientific research and critique of the scent identification. It further noted that for some groups of means of evidence, including the scent identification, the law and case law set certain minimal requirements (standards) for their use in criminal proceedings. Special nature of the scent identification method requires that these requirements must be strictly complied with. Moreover, it requires that the criminal courts duly reflect the latest state of scientific research into the field of scent identification, especially in relation to its reliability and accuracy. Compliance with these requirements gains special prominence when there is a general lack of either direct evidence or at least clear and convincing circumstantial evidence in the proceedings, such as in the present case.

In such cases, it is necessary that the scent identification be carried out in compliance with more than the minimum requirements, especially if it was carried out pursuant to the old – now replaced – legal provisions which did not reflect the most recent scientific findings in the field of scent identification.

In the opinion of the Constitutional Court, the scent traces were the key and, in fact, the only evidence of the guilt of both complainants, as none of the witnesses was able to clearly identify them as perpetrators. All the witnesses described the alleged perpetrators in very general terms, namely that one was taller and the other was shorter. However, in no way did they describe the perpetrators in such a clear and detailed way as to suggest that they were identical to the complainants.

The Constitutional Court thus concluded that the guilt of the complainants was not proven beyond reasonable doubt, based on sufficient evidence and properly substantiated in the criminal proceedings. The contested decisions of the criminal courts therefore violated the principle in dubio pro reo which flows from the principle of the presumption of innocence under Article 40(2) of the Charter and Article 6(2) of the Convention. They also infringed the complainants' right to a fair trial under Article 36(1) of the Charter.

III. Pavel Šámal served as Justice-Rapporteur. No Justice dissented.