No, I don't believe that J. Edgar Hoover or anyone else covered up details about the John F Kennedy assassination. I think that we know a great deal about the assassination and what happened and I don't think that it is plausible that Lee Harvey Oswald had anyone else assisting him that day.
No, I do not believe that J. Edgar Hoover was able to cover up details about John F. Kennedy's assassination. The details of that terrible day in American history are well established, and have been investigated from every possible angle by hundreds of credible researchers. There's just no conspiracy to be found.
The JFK Assassination is an incredibly well covered and well researched event that people refused to accept because he was beloved and people couldn't believe it, and happened at a time when people were losing trust in the government. The FBI of the time was dirty - but this wasn't on them.
J. Edgar Hoover did not cover up details about the John F. Kennedy assassination. JFK's killing was investigated so many times and from so many different angles that there was no way a cover up could have occurred. Too many loose ends would have been the result. There are not many loose ends in this case.
I do not think that J. Edgar Hoover covered up any details about the death of John F. Kennedy. I think the government was very open about what happened and felt the loss as much as anyone else did. It was a sad thing that happened and I do not believe their was a conspiracy behind it.