As the podcast nears its conclusion, fresh information kept hidden in UK Foreign Office files for 40 years delivers yet another twist to this case.
Martin Bottomley of the Greater Manchester Police Cold Case Unit gives an unexpected reply to a question Dan hesitates to ask - and it becomes clear this story is far from over.
And Boston's public defender, Lexi Nagin, reveals she's an avid listener to the podcast - but hasn't changed her mind about her client.
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BBC Radio 5 Live. Innehållet i podden är skapat av BBC Radio 5 Live och inte av,
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