If a person commits a offence by the state but that does not get caught by relevant authorities, should he surrender himself to the authorities and tell them about this offence ?
no you don;t have to go to police office
allah say in 5. Al-Maaida (The punishment of those who wage war against Allah and His Messenger, and strive with might and main for mischief through the land is: execution, or crucifixion, or the cutting off of hands and feet from opposite sides, or exile from the land: that is their disgrace in this world, and a heavy punishment is theirs in the Hereafter(33)Except for those who repent before they fall into your power: in that case, know that Allah is Oft-forgiving, Most Merciful.(34))