Brennan was a dodgy guy, and blind as a bat , he working as a plumber in the train yards behind the Plaza, for the protestant Wallace clan, and I would not be surprised to find out he was a KKK member, or somehow connected to the radical right, and Mr Mac Wallace.
He could not i.d Oswald in the lineup and went home, he then seen him on T.V the F.B.I told him Lee was a Commie and he then made a positive id after Ruby killed him.
The paraffin test proved Howard to be a lier