* Kennedy was probably killed as a result of a conspiracy.
* Four shots, not three, were fired during the assassination.
* One shot was fired from the grassy knoll. The shot from knoll missed both Kennedy and the limousine.
* Impulses caused by four gunshots were recorded on a police dictabelt recording that was made by a patrolman's mike that was stuck in the "on" position as his motorcycle rode near and through Dealey Plaza during and after the shooting. The committee's acoustical scientists concluded that an analysis of the recording revealed, to a degree of certainty of 95 percent or better, that one of the shots could be traced back to the grassy knoll.
* Jack Ruby had significant ties to organized crime.
* Ruby probably did not enter the PD basement via the Main Street ramp, and might have gained access to the basement by help from someone on the police force.
* Ruby lied to the Warren Commission about the number and nature of his trips to Cuba prior to the assassination.
* In the months leading up to the assassination, Ruby made long-distance phone calls to organized crime contacts, and some of these phone calls did not appear to have a viable innocent explanation.
* Ruby's killing of Oswald was not a spontaneous act but had the appearance of a hit designed to silence Oswald.
* The Warren Commission failed to adequately investigate the possibility of conspiracy.
* The FBI and CIA were deficient in supplying the commission with information in their possession that related to the assassination.
* The security arrangements for the Dallas motorcade may have been uniquely insecure.
* The pathologists who performed Kennedy's autopsy failed to perform a proper medical-legal autopsy.
* Analysis of the photographic evidence revealed that Kennedy was hit by a bullet as the limousine passed beneath the oak tree. Even though this shot came at a time when a gunman's view of Kennedy from the Depository's sixth-floor window would have been obscured by the oak tree, the committee concluded the shot came from that window.

In addition, the HSCA endorsed the Warren Commission's conclusion that Kennedy and Connally were struck by the same non-fatal bullet, and that Oswald fired that shot and the head shot. The committee also agreed with the commission's finding that Oswald killed Tippit.

As for the conspiracy itself, the committee hinted in its report that elements of the Mafia might have been involved. The committee suggests that Mafia boss Carlos Marcello was involved in the assassination conspiracy.