Possible Clues:

• 'A person of importance?': murder detective's first question?
• "Who wants to volunteer?"
• Word encouraging class participation
• ''Do I have a volunteer?''
• 'Who wants to try?'
• "Who'll volunteer?"
• Possible description of the UN for people in general
• "Volunteer?"
• Some random person that the snatchers were after?
• Evidence someone's been murdered - doesn't matter who