The mystery began on New Year's Eve, when Wheeler's body was discovered in the Wilmington-area dump after it was left by a garbage truck.
His death was quickly ruled a homicide, but a criminologist told "The Early Show on Saturday Morning" authorities may have moved too quickly in that declaration, and that there are other plausible possible causes of death.
Wheeler was a graduate of West Point who served as an aide to three presidents and led the effort to build the Vietnam Veteran's Memorial,
He appeared unhinged in the days before his death, reports CBS News correspondent Michelle Miller. Surveillance video caught Wheeler in a Wilmington parking garage two days earlier, looking disoriented. He wasn't wearing a coat and was carrying one shoe.
"His face was really flush," parking attendant Iman Goldsborough told CBS News. "From the way his shoe looked, I would say it looked like somebody had done thing to him."
The next night, Dec. 30, Wheeler was seen at another building in Wilmington, dressed in different clothes and again looking confused.
Police say somehow, Wheeler's body ended up in a dumpster 15 miles away.
A neighbor who had seen Wheeler Christmas Eve says he has no idea what might have happened, and was shocked at Wheeler's condition on the tape.
"I have never seen him like that in my life," Robert Dill told CBS News. "I have no idea. At this point, I couldn't even give you a theory."
Wheeler's car was found parked at a train station.
Miller says investigators have been eyeing a legal battle Wheeler was having with a neighbor whose home is under construction.
In a new development that's raising even more questions, a local TV station is reporting that Wheeler's cell phone was found inside that home.
But, friends say they can't imagine that dispute would have led to Wheeler's death.
On "The Early Show on Saturday Morning," criminologist Casey Jordan. of Western Connecticut State University, in Danbury, pointed out that authorities called Wheeler's death a homicide within 24 hours of his body being found. "That's a logical thing to assume," she told co-anchor Rebecca Jarvis, "based on the fact that his body was n a dump and had been placed in a dumpster. But, we still don't know the actual cause of death. To be honest, that's a little bit of a jump. Usually, you know the cause of death before you decide the manner of death is a homicide. That was, of course, before we had seen the (surveillance) footage (and) we understood about this disoriented state that happened in the two days before he was found.
"And I wouldn't be surprised if they end up changing that after they get the toxicology reports come back. I think the autopsy isn't complete and we need more details before we decide whether or not he was murdered.
"What's confusing to me is that, usually, you know that (someone was killed) because you have something like a gunshot wound, stabbing wounds, bludgeoning -- something that clearly could not have been self-induced. But no details like that have been released.
"And the fact of the matter is that, when we see this footage, we see perhaps he was suffering from an organic brain problem? Even his neighbors say they'd never seen him like this. Was he poisoned? Did he have a brain tumor? Did he suffer from brain cancer and nobody even knew it? Something -- there's a disconnect between him being in the dumpster and that behavior we see in the hours before he disappeared.
" … There are possibly 10 dumpsters he came from that ended up in that dump truck, so we don't even have a crime scene. It is entirely possible he crawled into the dumpster himself in his demented state.
"We may never know the truth about what happened to John Wheeler."
To see the entire interview, click on the video below: