From "Murder From Within" on the gunpowder "nose witnesses:"
***Motorcycle escort officer Billy J. Martin, riding one-half car length from the left rear fender of the Presidential limousine, recalled, “You could smell the gunpowder… you knew he wasn’t far away. When you’re that close, you can smell the powder burning. Why you—you’ve got to be pretty close to them… you could smell the gunpowder… right there in the street.”63 (Figure 3-7) “Nose” witnesses Sen. Ralph Yarborough rode in the second car behind the limousine. He smelled gunpowder in the street64 and said it clung to the car throughout the race to Parkland Hospital.65 He later commented, “. . . you don’t smell gunpowder unless you’re shooting at something up wind and it blows it back in your face…”65-a As noted, the motorcade headed into a breeze—photographs show bystanders’ skirts billowing in the wind. At Parkland Hospital Yarborough told reporters “the third shot may have been a Secret Service man returning fire”.65-b Two cars behind Yarborough was the Cabell car. Elizabeth Cabell said she “. . . was acutely aware of the odor of gunpowder.”66 She added Congressman Ray Roberts, seated next to her, had mentioned it also.67 According to press photographer Tom C. Dillard, two cars behind the Cabell car, he “. . . very definitely smelled gunpowder when the cars moved up to the corner [of Elm and Houston Streets].”68 Bystander Virgie Rackley stood in front of the depository building close to the street. “She recalled that after the second shot, she smelled gunsmoke…”69 At the time of the shots, patrolman Joe M. Smith moved from the intersection of Elm and Houston Streets toward the triple underpass.70 Patrolman Earle V. Brown, stationed 100 yards west of the underpass, heard the shots and then smelled gunpowder as the car sped beneath him.71 A police officer who was on the sixth floor of the depository shortly after the shooting failed to smell any gunpowder there.72 One newspaper summed it up: “. . . seconds later the cavalcade was gone. The area still reeked with the smell of gunpowder.”73 Shots from the sixth floor of the depository building would have caused no gunpowder smell in the street. ***