No, Brennan only saw the person with the rifle for a few seconds. The question is, did he know it was the same person he saw earlier without a rifle (based on what?) or did he just assume it?
If you are suggesting he saw two (or more?) different men, then you really should consider providing some evidence of that. Brennan indicates that it was only one man.
VOLUNTARY STATEMENT. Not Under Arrest Form No. 86
SHERIFF'S DEPARTMENT
COUNTY OF DALLAS, TEXAS
Before me, the undersigned authority, on this the 22 day of November A.D. 1963 personally appeared Howard Leslie Brennan, Address 6814 Woodard, Dallas, Texas Age 44 , Phone No. EV 1-2713
Deposes and says:
I am presently employed by the Wallace and Beard Construction Company as a Steam fitter and have been so employed for about the past 7 weeks. I am working on a pipe line in the Katy Railroad yards at the West end of Pacific Street near the railroad tracks. We had knocked off for lunch and I had dinner at the cafeteria at Record and Main Street and had come back to see the President of the United States. I was sitting on a ledge or wall near the intersection of Houston Street and Elm Street near the red light pole.
I was facing in a northerly direction looking across the street from where I was sitting. I take this building across the street to be about 7 stories anyway in the east endof [sic] the building and the second row of windows from the top I saw a man in this window. I had seen him before the President's car arrived. He was just sitting up there looking down apparently waiting for the same thing I was to see the President. I did not notice anything unusual about this man. He was a white man in his early 30's, slender, nice looking, slender and would weigh about 165 to 175 pounds. He had on light colored clothing but definately [sic] not a suit. I proceeded to watch the President's car as it turned left at the corner where I was and about 50 yards from the intersection of Elm and Houston and to a point I would say the President's back was in line with the last windows I have previously described I heard what I thought was a back fire. It run [sic] in my mind that it might be someone throwing firecrackers out the window of the red brick building and I looked up at the building.
I then saw this man I have described in the window and he was taking aim with a high powered rifle. I could see all of the barrel of the gun. I do not know if it had a scope on it or not. I was looking at the man in this windows at the time of the last explosion.
Then this man let the gun down to his side and stepped down out of sight. He did not seem to be in any hurry. I could see this man from about his belt up. There was nothing unusual about him at all in appearance. I believe that I could identify this man if I ever saw him again.
/s/ H. L. Brennan
/s/ C. M. Jones
Notary Public, Dallas County, Texas