To any reasonable person.
In order to have an investigation one needs some evidence that gives some reason to suspect that JFK faked his death and that the abundant evidence that he didn't was false.
Some facts are so clear that an investigation is not warranted. For example, it is proven that Hitler lost WWII As far as I can see, no one has ever investigated whether he lost. Similarly, no one will ever investigate whether JFK really died. It is obvious to any reasonable person that he died on 22Nov63.
Well, what a reasonable person see after 58 years now is that there is something very wrong with the official story told by the Warren Report. When I started researching, I wanted to see is there something else besides WR, LN, CT... My research lead me to a conclusion that JFK did not die that day in Dallas.
No, I do not have evidences in my possession but they do exist. One of them is Dr. Robert N. McClelland blood stained shirt he wore at the Trauma room 1. National Archives have cloths JFK wore that day, too. Would be interesting to see what the DNA analysis would bring as a result. Also, several participants are still alive such as Clint Hill and Caroline Kennedy who were never asked this question.
If you are a reasonable person in 21st century, knowing everything you know about US politics of deceptions, conspiracies and cover-ups in the last 5-6 decades, I am sure you will be able to at least accept possibility that there is something else that might happen in Dallas that day.