JD Tippit
Dallas PD officer killed in aftermath of assassination

Officer Tippit was driving through a quiet residential neighborhood shortly after President Kennedy was shot. Already the word was out to watch for someone matching the description of Lee Harvey Oswald. The official story goes that he saw Oswald and pulled his car over to talk to him. It is said he rolled the window down on the passenger side and they spoke briefly.
It is then that he exited his vehicle and was promptly shot twice, with the shooter then walking around the care and shooting him one more time in the head. We are told that the shooter then ran down the street, ditching his jacket under a vehicle in a used car lot.
A short time later investigators arrived on the scene followed by television news crews. The investigators found four spent shells from two different manufacturers and a wallet. The news crew filmed the police activity and were shown the shells and the wallet which had the identification of Lee Harvey Oswald. Case closed!
This would have worked out nicely except for the fact that when Oswald was captured he still had his wallet and the gun he was carrying was a revolver – and revolvers do not eject spent cartridges. Beyond that, after police examined the weapon they found that the firing pin was bent and it could not be fired.
Investigators also had a timeline issue as adjusted the time of the shooting several times from the witness accounts in order to have it fit into the official narrative of Oswald returning to his rooming house and eventually arriving at the Texas Theater.
Perhaps the most troublesome detail the investigators dealt with was the description of the shooter. Helen Marcom gave a dramatic account of the event as did Acquila Clemons. He was described as a heavier balding man. Some even saw an accomplice. The pair described could easily have been Jack Ruby and Lyndon Johnson enforcer Mac Wallace. As you can see in her video Ms Clemons was told it would be best if she didn't talk about it or she could get hurt.