In criminal cases, the testimony of a police officer is often an important piece of evidence. However, a more difficult question arises: can a person be convicted when the only evidence against them is, in substance, the word of a police officer?
Under Article 82 of the Criminal Procedure Code of Georgia, no evidence has predetermined evidentiary value. Accordingly, the testimony of a police officer cannot carry greater weight than that of any other witness merely because of the officer's official status.
The issue becomes particularly problematic when the police officer personally participated in the events about which they later testify in court.
For example, a police officer claims to have seen a person discard narcotics. The accused denies it. There is no video recording, no independent witness and no other objective evidence. The court is therefore left with two conflicting accounts.
Why should the police officer's version automatically be regarded as more credible?
The European Court of Human Rights addressed this issue in Navalnyy and Yashin v. Russia. The Court attached particular importance to the fact that the only witnesses for the prosecution were the same police officers who had directly participated in the events in dispute.
According to the Strasbourg Court, in such circumstances domestic courts must make use of every reasonable opportunity to verify the credibility of the incriminating statements made by police officers. The ECtHR linked this requirement to the prosecution's burden of proving guilt and to the principle of in dubio pro reo, under which unresolved doubt must operate in favour of the accused.
This does not mean that police testimony is inherently unreliable or that the existence of only one witness automatically precludes a conviction. The point is different: a police officer's official status gives their testimony neither special evidentiary weight nor a presumption of credibility.
A court's reasoning therefore cannot be reduced to the question: “Why would the police officer lie?”
The central question in criminal proceedings is different:
Has the prosecution proved the person's guilt beyond a reasonable doubt?
If the court has nothing more than disputed police testimony unsupported by objective evidence, that testimony requires particularly careful scrutiny. A person's liberty cannot depend solely on an assumption that a state official is telling the truth.
