There may be no legal solution to your concern (and, remember, this Q&A is for legal questions) but two practical ideas are: 1) try to interest the Idaho Falls newspaper in some investigative reporting; and 2) remember that your county sheriff is an elected official, so in theory you could elect one willing to reopen the investigation. You do not mention how many "years ago" and I don't remember the situation, so be aware that time may not be on your side.
Best wishes for an outcome you can accept, and please remember to designate a best answer.
This answer is offered as a public service for general information only and may not be relied upon as legal advice.
For a not for profit group. Raise money. Hire a criminal defense attorney that does private investigations and wrongful death actions. NACDL.org
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