Upon referrals by States Parties or by the UNSC, or on its own initiative and with the judges' authorisation, the Office of the Prosecutor (OTP) conducts investigations by gathering and examining evidence, questioning persons under investigation and questioning victims and witnesses, for the purpose of finding evidence of a suspect's innocence or guilt. OTP must investigate incriminating and exonerating circumstances equally. OTP requests cooperation and assistance from States and international organisations, and also sends investigators to areas where the alleged crimes occurred to gather evidence. Investigators must be careful not to create any risk to the victims and witnesses.