The Criminal Justice Act 2006 significantly strengthens investigatory and prosecutorial powers and modernises evidence and firearms law. It provides statutory crime‑scene powers, broadens search and seizure and detention provisions, updates forensic sampling and permits certain recorded witness statements to be admissible. The Act creates limited prosecution routes to the Supreme Court on points of law, tightens explosives and fireworks offences and introduces restricted firearm categories, firearms training certificates and mandatory minimum sentences for serious firearms offences.

The Act also targets organised crime and drug trafficking by creating new conspiracy and facilitation offences, raising import/value thresholds and imposing post‑conviction notification obligations. Sentencing reforms permit suspended sentences, deferred custodial penalties, restriction‑on‑movement orders and electronic monitoring. It adds civil remedies for anti‑social behaviour, reforms youth justice (raising the minimum age of criminal responsibility with narrow exceptions and transferring detention functions) and establishes a Criminal Law Codification Advisory Committee.