Kevin Dietz, an investigative reporter from Channel 4, asked himself the above question. He contacted Western Ontario University which has a program that investigates cold cases. The University had the matter investigated by staff and students. The 25 page report from Western Ontario University concluded that it could have been either murder or suicide, but murder was the better possibility.
In 2015 I was contacted by Anthony Karrick who was writing a book claiming that Busch has been murdered by the OCCK perpetrators because he had attempted to bribe them to remain silent. Although we met 3 times, he never did give me any factual information supporting his conclusion. He advised me that he had met with the Oakland County Sheriff on this issue but had not received any formal report from that office. Karrick died the day after our third meeting.
It is my understanding that the concurrent investigators and prosecutors do not eliminate the murder possibility. Realistically, there is little likelihood at this late date they will charge anybody with murder unless much more information is available.