the principle of equality of arms in preliminary investigation phase in iranian criminal procedure code 2013 and international human rights instruments

the principle of equality of arms means that each party in an action shall present her claim in an environment so that this does not put him in a worse condition compared to the other party of the trial. this principle has been internationally and locally embraced by authorities. from the perspective of international documents, the acceptance of this principle is partly influenced by the acceptance of global principle of fair trials which has been shaped by a shift toward the criminal justice system, especially in preliminary investigation phase. this requires that at the first encounter of the accused, the victim and etc. with the criminal justice system that is formed on the basis of a criminal case, i.e. police preliminary investigation phase, facilities of the aforementioned persons shall be specified and basic rules are predicted in law in order to comply with them. fortunately, iranian criminal law which was approved in 2013 has generally considered acceptance of the principle of equality of arms inspired by international documents as one of the strategic principles of criminal law and apparently has predicted some of the basic rules of the principle of equality of arms at the judicial police investigation phase and it has established some of the regulations based on the alignment of each party in a claim. however, these innovations are confronted with limitations in some criminal cases and have inevitably tarnished the total equality of the parties including the relative balance of the accused, the prosecuting attorney and the victim at the police investigation phase.