John F. Kennedy was assassinated nearly 50 years ago on Nov. 22, 1963.

Investigations by the FBI, the Dallas Police Department and the Warren Commission collectively concluded that Lee Harvey Oswald, a former U.S. Marine, had been the sniper who shot and killed Kennedy.

However, the aftermaths of the tragedy also created an emergence of various theories as to why the then-U.S. president had been killed and who had done it.

Physician and author Dr. Richard Buyer, M.D., wrote a book about what he alleges is the truth behind the JFK assassination, "Why the JFK Assassination Still Matters - The Truth for My Daughter Kennedy and for Generations to Come."

Buyer was a senior in college when Kennedy was campaigning to become president.

"Just to hear him talk and watch his mannerisms," he said. "He was extremely charismatic, dignified...he was the first president I voted for. And then he was assassinated...I grieved as everyone else for four days...but life goes on."

All of a sudden, Buyer found himself picking up book after book about the assassination. He said he's probably read about 250 books on the topic. And, after all that research, he said he felt the impression that what he and everyone had been told about the assassination was not true.

Buyer's daughter, Kennedy, is mentioned in the book's title. Her birthday happens to land on the same date Kennedy was killed.

"Once I had developed my own ideas after all this research I had done, I happened to go to Kennedy's school and looked in their history books," he said. "Essentially...they were being fed the same material that I was fed...that Oswald was the killer of President Kennedy, and I feel that is a lie. I was lied to, and I don't want my daughter lied to...and any future generations lied to."

As the assassination's 50th anniversary approaches, Buyer said he hopes the book on what he thinks truly happened has not been closed.

"Because if it did, we have an inaccurate interpretation of history," he said.