Seriously, if DPD officer Bakers purpose for running towards the TSBD was because he thought the gunman might be on an upper floor of the building , then his primary goal was to go to the TSBD entrance door, rather than anywhere else.
Perspective lines need be verified by a computer model before just relying on somebody who drew 2 blue lines overlayed on the Darnell film segment to declare with any certainty that Baker was not heading for the steps.
Even if the perspective lines can be verified, it’s still doubtful Baker would have been distracted enough by some person with a paper , to stop and waste time , rather that continuing his primary goal to find the shooter he suspected was still on an upper floor of the TSBD.