Does an unlawful arrest affect any subsequent criminal prosecution?

The notion that an unlawful arrest does not affect any subsequent criminal prosecution is rooted in the principle known as the "harmless error" doctrine in criminal procedure. This principle asserts that a defendant cannot automatically seek dismissal of charges based solely on the illegality of their arrest if the prosecution has sufficient evidence to convict them independently of that arrest.

In many jurisdictions, even if an arrest is deemed unlawful, the admissibility of evidence obtained or the validity of the prosecution can remain intact. The rationale behind this is that the legal system prioritizes the determination of guilt or innocence based on the merits of the evidence presented in trial, rather than on procedural missteps that may have occurred prior to the arrest.

The criminal justice system balances the rights of the individual against the need to uphold public safety and the enforcement of laws, suggesting that while unlawful arrests may result in remedies such as suppression of evidence obtained during the illegal detention, they do not necessarily invalidate the prosecution's case entirely.

Thus, the view that an unlawful arrest does not affect any subsequent prosecution aligns with the understanding that the existence of adequate evidence independent of the circumstances of the arrest can sustain criminal charges.