I'm no specialist but have followed this topic throughout the year's. There was no blood spatter analysis in 1963, the year the assassination happened. Since then blood spatter analysis was invented, perfected, and became a standard technique by law enforcement in murder investigations.
Sheri Fiester, now deceased, was a retired blood spatter analysis expert and looked at the Zapruder film of the assassination. She noticed that the blood coming out of jfk's head exited in a forward direction during the fatal shot, indicating that the shot came from from the direction of the blood spatter, I.e. the front.
She went to the scene of the crime and walkes through delay plaza. In her opinion, based on her training, experience, and videographic evidence depicted in the Zapruder film, the fatal shot came from the triple underpass area- which aligned perfectly with the position of the limo on Elm Street at the time of the fatal shot, direction of the blood spatter, etc.
When you see the zapruder film, you can see that the front of the limo makes a slight turn to the left due to the curvature of Elm Street and, therefore, places jfk facing directly forward towards the left side/opening of the triple underpass- which is very dark and provides cover for a person.
Sheri fiester spoke at her sister's gathering in Dallas as part of Jfk Lancer.org or .com.
MS. Fiester has also said that expert snipers had infotmed her that when hit teams are assembled to eliminate a target or political leader, they work in groups of three (3) members, so as to create a distraction prior to the fatal shot. This may explain why people ran towards the grassy knoll after the final head shot and why some witnesses said they saw a rifle and heard shots from the 6th floor of the Texas Schoolbook Depository (Texas Governor John Conally also testified he heard shots from behind where he was seated in the limo)...there was a shooter behind the fence in the grassy knoll and another in the texas schoolbook depository, both of whom fired a weapon prior to the shooter firing the fatal shot from the triple underpass.
Sincerely, Joel Peralez