From Ruby's WC testimony:
Mr. RUBY. I had the gun in my right hip pocket, and impulsively, if that is the correct word here, I saw him [i.e., Oswald], and that is all I can say. And I didn't care what happened to me.
I think I used the words, "You killed my President, you rat." The next thing, I was down on the floor.
I said, "I am Jack Ruby. You all know me."
I never used anything malicious, nothing like s.o.b. I never said that I wanted to get three more off, as they stated.
The only words, and I was highly emotional; to Ray Hall--he interrogated more than any other person down there--all I believe I said to him was, "I didn't want Mrs. Kennedy to come back to trial."
Ruby admitted he was there, he admitted to firing his revolver - he didn't want to "get three more off". If Ruby didn't shoot Oswald then why is he admitting to all of this?