Mr. Hubert. Would you care to state for the record, Chief Stevenson, what, in your opinion, was the cause of the breakdown of security which resulted in the death of Oswald?
Mr. Stevenson. Mr. Hubert, I don't know whether I can tell you the cause or not, but there is no doubt we had a breakdown. And if our investigation is right, it was at the Main Street ramp into the basement through which Ruby claimed that he walked down that ramp while this officer had his back turned. And our investigation showed that he did leave the Western Union Office some 4 or 4½ minutes prior to the shooting.
Our breakdown, although this is my opinion, it was unintentional on the part of Officer Vaughn, in my opinion, he did come down that ramp.
Mr. Hubert. Is there anything else you would like to say, sir, concerning any part of this matter whatsoever?
Mr. Stevenson. Mr. Hubert, I don't recall a thing that I haven't attempted to cover. However, if there is anything that I have not covered, I will be glad to attempt to or to answer any questions that you might think pertinent to it, and anything that I have failed to cover has been unintentional, I assure you.
Mr. Hubert. I simply want to give you an opportunity now to say anything else that you might want to say, realizing, of course, that there may be other things which don't come to your mind at the moment, but I would like you to think about it and tell us if there is anything at all that has not appeared in any statement you have made or in any part of this deposition.
Mr. Stevenson. The only thing that I could say that comes to my mind at the present is, up until Oswald was killed in the basement, we felt like we had built a good case on Oswald as the slayer of President Kennedy, and we felt we had done a good job on the arrest and the accumulation of the evidence.
We just had a breakdown. We were let down unintentionally, in my opinion, from the investigation, by one officer that permitted Ruby to get into the basement.
Mr. Hubert. Have you made any other statement, Mr. Stevenson, other than those that you have identified as Exhibits 5051 and 5052?
Mr. Stevenson. Not to my knowledge that I recall, other than the overall chronological report that we made to the chief of police regarding the entire operation and plan for the visit of the President all the way through until Oswald was slain by Ruby in the basement.