An amnesty offered to whom, for what and by whom?
I have read of amnesties offered in some situations in the UK, but I'm not sure about PT. I'm thinking of, e.g., if someone witnessed or later discovered what happened to her, but hasn't come forward due to fear of prosecution for comparatively minor illegal activity.
I don't recall any instances of amnesty for anyone responsible for serious crimes, such as abduction, sexual abuse or murder.
Could an amnesty be offered if someone knew that she was being kept in captivity and hasn't reported due to fear of prosecution for being an accessory after the fact?
It's not clear which prosecuting authority would need to make any such decision.
While charges would normally be brought against those responsible in the country in which the crime was committed, there appear to be exceptions.
Resolving jurisdictional conflicts
Where the offence occurred on a single territory
Generally, an offence will only be triable in the jurisdiction in which the offence takes place, unless there is a specific provision to ground jurisdiction, for instance where specific statutes enable the UK to exercise extra-territorial jurisdiction:
sexual offences against children (section 72 of the Sexual Offences Act 2003) A new section 72 was substituted by the Criminal Justice and Immigration Act 2008 which came into effect from 14 July 2008 onwards. It is important to ensure that any prosecution is brought under the provision in force at the time the alleged conduct occured as the terms of the substantive provisions and details of the offences they cover are not identical;
murder and manslaughter (subsection 9 and 10 of the Offences Against the Person Act 1861)
fraud (the 2006 Act imposes extra territorial jurisdiction in respect od offences in subsection. 1, 6, 7, 9 and 11 of the Fraud Act 2006) and dishonesty (Criminal Justice Act 1993 Part 1 still applies to the remaining unrepealed sections of the Theft Act 1968);
terrorism (subsection 59, 62-63 of the Terrorism Act 2000 and section 17 of the Terrorism Act 2006);
bribery (The Bribery Act 2010 repeals the common law and the statutory offences of corruption for offences committed wholly on or after 1 July 2011. For those offences the Bribery Act imposes extra-territorial jurisdiction. Section 109 of the Anti-Terrorism and Security Act 2001 still applies to provide extre-territorial jurisdiction in respect of offences committed wholly or partially before 1 July 2011.
For a list of particular offences with an extra-territorial reach see Archbold .http://www.cps.gov.uk/legal/h_to_k/jurisdiction/However...
There is this:
http://www.legislation.gov.uk/ukpga/2003/42/section/72and this:
http://www.legislation.gov.uk/ukpga/Vict/24-25/100