Author in the work analyzes the provisions of two European legislations, in which the preliminary phase of criminal procedure is differently regulated in its basis. The role of public prosecutor and judicial police in Italy and Spain comes from the foundation of Constitution which supplies necessary guarantees of fundamental human rights and freedoms and separations of powers. The matters of consideration are concept of judicial police, power of judicial police and public prosecutor and mechanisms of efficiency of public prosecutor unto performance of police affairs and the position of police officers. The aim of the work is to select tendencies through the comparative law analysis along with critical review, to point out the examples of acceptable and necessary solutions, as well as the need for adjustment of law of Republic of Serbia and the directions of future reform of legal and procedural position and the relations between the authorities conducting proceedings. The visible thing is the tendency of introduction of public prosecutorial investigation. In Republic of Serbia, the powers of independent court authority are transferred unto the public prosecutor who do not carry the privilege of independence that is necessary assumption on account of achievement of separation of powers. Additionally, the new role of public prosecutor demands the adjustment of procedural provisions concerning the new legal instruments and mechanisms.Autor u radu analizira odredbe dva evropska zakonodavstva u kojima je prethodna faza krivične procedure u osnovu različito regulisana. Uloga javnog tužioca i sudske policije u Italiji i Španiji izvire iz ustavnih temelja koji pružaju neophodne garancije osnovnih ljudskih prava i sloboda i podele vlasti.
Predmet razmatranja su pojam sudske policije, ovlašćenja sudske policije i javnog tužioca i mehanizmi delovanja javnog tužioca na obavljanje policijskih poslova i položaj policijskih službenika. Cilj rada je da se putem uporednopravne analize uz kritički osvrt izdvoje tendencije, da se istaknu primeri prihvatljivih i nužnih rešenja, kao i potreba usklađivanja prava Republike Srbije, te pravci buduće reforme pravnog i procesnog položaja i odnosa organa postupka.
Uočljiva je tendencija uvođenja javno – tužilačke istrage. U Republici Srbiji, na javno tužilaštvo se prenose ovlašćenja nezavisnog sudskog organa, a javnotužilašvo ne uživa garancije nezavisnosti, što je neophodna pretpostavka radi ostvarivanja podele vlasti. Pored toga, nova uloga javnog tužioca zahteva usklađivanje procesnih odredaba u pogledu novih pravnih sredstava i mehanizama
