Court decisions pertinent to the investigation of crime focus on the exclusionary sanction, constitutional doctrines related to law enforcement conduct, the issuance and execution of arrest and search warrants, the detention of persons and related searches, warrantless searches, interrogation and confessions, undercover investigations, and grand jury investigative functions. Issues discussed in relation to the exclusionary sanction are the adoption of the Federal constitutional exclusionary sanction, the "standing" fruit of the poisonous tree and attenuation of the taint, and good faith and other exceptions. The court decision on the issuance and execution of arrest and search warrants considers the requirement of particularity and execution of warrants. Topics in court decisions on warrantless searches include the emergency doctrine, consent searches, and automobile searches and seizures. Court decisions relevant to prosecution and adjudication address the initial appearance and detention, the preliminary examination and the grand jury, the right to a speedy trial, competency to stand trial, discovery and disclosure, right to an impartial trial, joinder and severance of charges and defendants, double jeopardy, adjudication of guilt by plea, adjudication of guilt or innocence by trial, effective assistance of counsel, sentencing, and appeal and collateral attack. A table of cases is provided.