Judicial Discretion in Evidence Admissibility: A Critical Analysis of Reliability, Bad Faith, and the Protective Principle

Michael Doherty, in his work on judicial discretion, highlights three key frameworks for evaluating the admissibility of evidence: reliability, bad faith, and the protective principle. These frameworks provide a lens through which courts can assess the legality and fairness of police conduct in obtaining evidence.

Reliability Principle

The reliability principle centers on the methods used by law enforcement to obtain evidence. Doherty argues that if the method employed could potentially compromise the reliability of the evidence, then that evidence should be excluded. This principle aligns with the views of Ormerod & Birch, who suggest that courts are more inclined to exclude evidence when its reliability is called into question.

A prime example of this principle in action is the case of R v Cooke. In this case, police officers used physical assault to obtain hair samples from the suspect. Despite the unlawful method of obtaining the evidence, the court deemed the hair samples admissible because their reliability remained intact.

Conversely, in the case of Stewart, the defendant was convicted of abstracting electricity and stealing gas. Electricity company officials, accompanied by police, entered the defendant's house under arguably unlawful circumstances and discovered a device used to bypass the meters. The Court of Appeal held that it was unnecessary to determine the legality of the entry because even if it were unlawful, the admission of the evidence did not impact its fairness, unlike evidence obtained through a breach of Code C (the code governing detention and questioning of suspects).

Bad Faith Principle

While the Court of Appeal has stated that it is not the court's role to discipline the police, it is evident that evidence obtained in bad faith is more likely to be excluded. Doherty posits that the bad faith principle advocates for the exclusion of evidence obtained through police misconduct as a means of holding officers accountable for their actions.

Determining whether police conduct constitutes misconduct often involves examining compliance with Code C. A breach of Code C can lead to the exclusion of evidence. The significance of the breach is left to the discretion of the judges.

However, a significant challenge lies in the court's approach to bad faith. Courts tend to exclude evidence only in extreme cases where deliberate bad faith on the part of the police can be demonstrably proven. This high threshold for exclusion raises concerns about the effectiveness of this principle in curbing police misconduct.

The case of Matto v Wolverhampton Crown Court exemplifies this challenge. The court ruled that a breath specimen obtained in breach of Code C should be excluded under Section 78 of the relevant legislation. This decision highlights the court's recognition of the importance of upholding procedural fairness and the need to deter police misconduct, even in cases where the reliability of the evidence itself might not be in question.

Conclusion

The principles of reliability, bad faith, and the protective principle are essential tools in ensuring fairness and justice within the criminal justice system. While the reliability principle focuses on the integrity of the evidence itself, the bad faith principle seeks to address the conduct of law enforcement. However, the high threshold for proving bad faith poses a challenge to its effectiveness. Striking a balance between these principles is crucial to safeguard both the rights of the accused and the integrity of the judicial process.