Maybe he took Shasta for a friend's "use"?
While a possibility, he held Shasta for some time, probably the entire six weeks. This begs the question: Why would he hold onto such a dangerous "commodity" for so long?
There is much to this sordid and tragic story that only Mr Duncan can provide, but he isn't talking. There are a *lot* of unanswered questions here, and getting to the bottom of the whole mess is something I don't envy law enforcement...
the infowarrior