Was Oswald a person of interest to the FBI and perhaps to the CIA prior to the assassination? If he wasn't, he should have been. Indeed, one of the great failures of the US government was that he was not much higher on their radar.
@John_Scotus ...but MLKJr was...
@John_Scotus I remember years ago the stories coming out how J. Edgar hated the Kennedy family and he might have been in on it.
Was there a great bit of CYA at the FBI after the fact because of their failures to spot and stop the freak? Certainly. It is would be surprising if the CIA wasn't involved in some CYA as well.