Howard Leslie Brennan (March 20, 1919 – December 22, 1983)[2] was an American memoirist and steamfitter who was witness to the assassination of United States President John F. Kennedy in Dallas, Texas on November 22, 1963.

According to the Warren Commission, Brennan's description of a sniper he saw was probative in reaching the conclusion that the shots came from the sixth floor, southeast corner window of the Texas School Book Depository Building.

[3] Minutes after the Kennedy's assassination, Brennan quickly reported his observations to Dallas County Sheriff's Deputies.

[4]According to the National Archives, this description likely led to the radio alert sent to police cars at about 12:45 p.m., which described the suspect as white, slender, weighing about 165 pounds (75 kg), about 5 feet 10 inches (178 cm) tall, and in his early thirties.

[7] In his testimony, he spoke about how he watched the presidential motorcade from a concrete retaining wall at the southwest corner of Elm and Houston streets in Dealey Plaza, where he had a clear view of the south side of the Texas School Book Depository Building.

Brennan watched several people in and around the Texas School Book Depository and made special note of a man he saw appear at an open window at the southeast corner of the sixth floor, which was 120 feet (37 m) from where he was standing.

[11][12][13] During his testimony, Brennan stated that he watched the parade as the presidential limousine turned the corner at Houston and Elm and headed toward the railroad underpass.

During extensive questioning, he stated that at the time of the lineup, he believed the assassination was part of a conspiracy, and he was afraid for the safety of himself and his family if he could identify the shooter.

[26] In June 1967, the Associated Press released a 15-page report, prepared by journalists Bernard Gavzer and Sid Moody, that summarized the news agency's six-month investigation supporting the Warren Commission's findings; the report also addressed some of the allegations of its critics and accused them of building their cases upon deliberate omissions.

[27] Gavzer and Moody wrote that Warren Commission critics attempted to weaken the case for a shooter in the Texas School Book Depository by attempting to weaken Brennan's testimony, then discussed specific charges leveled by authors Edward Jay Epstein and Mark Lane.