[1][2][3] Four members of a local Ku Klux Klan (KKK) chapter planted 19 sticks of dynamite attached to a timing device beneath the steps located on the east side of the church.

Although the Federal Bureau of Investigation had concluded in 1965 that the bombing had been committed by four known KKK members and segregationists: Thomas Edwin Blanton Jr., Herman Frank Cash, Robert Edward Chambliss, and Bobby Frank Cherry,[6] no prosecutions were conducted until 1977, when Robert Chambliss was tried by Attorney General of Alabama Bill Baxley and convicted of the first-degree murder of one of the victims, 11-year-old Carol Denise McNair.

"[9] Birmingham's Commissioner of Public Safety, Theophilus Eugene "Bull" Connor,[10] led the effort in enforcing racial segregation in the city through the use of violent tactics.

[11] Their demands included that public amenities such as lunch counters and parks be desegregated, the criminal charges against demonstrators and protestors should be removed, and an end to overt discrimination with regards to employment opportunities.

[8] When the Southern Christian Leadership Conference (SCLC) and the Congress on Racial Equality became involved in a campaign to register African Americans to vote in Birmingham, tensions in the city increased.

The church was used as a meeting-place for civil rights leaders such as Martin Luther King Jr., Ralph Abernathy, and Fred Shuttlesworth, for organizing and educating marchers.

[8] It was the location where students were organized and trained by the SCLC Director of Direct Action, James Bevel, to participate in the 1963 Birmingham campaign's Children's Crusade after other marches had taken place.

One week before the bombing, Wallace granted an interview with The New York Times, in which he said he believed Alabama needed a "few first-class funerals" to stop racial integration.

The Cahaba Boys had formed earlier in 1963, as they felt that the KKK was becoming restrained and impotent in response to concessions granted to black people to end racial segregation.

Investigators also gathered numerous witness statements attesting to a group of white men in a turquoise 1957 Chevrolet who had been seen near the church in the early hours of the morning of September 15.

Following the assassination of John F. Kennedy on November 22, 1963, newly-inaugurated President Lyndon Johnson continued to press for passage of the civil rights bill sought by his predecessor.

One individual who went to the scene to help search for survivors, Charles Vann, later recollected that he had observed a solitary white man whom he recognized as Robert Edward Chambliss (a known member of the Ku Klux Klan) standing alone and motionless at a barricade.

Jackson testified that Chambliss had expressed frustration that the Klan was "dragging its feet" on the issue of racial integration,[18] and said he was eager to form a splinter group more dedicated to resistance.

"[95][96] On the same afternoon that Chambliss's guilty verdict was announced, prosecutor Baxley issued a subpoena to Thomas Blanton to appear in court about the 16th Street Baptist Church bombing.

It was part of a coordinated effort between local, state and federal governments to review cold cases of the civil rights era in the hopes of prosecuting perpetrators.

[101] They unsealed 9,000 pieces of evidence previously gathered by the FBI in the 1960s (many of these documents relating to the 16th Street Baptist Church bombing had not been made available to DA William Baxley in the 1970s).

[102] On May 16, 2000, a grand jury in Alabama indicted Thomas Edwin Blanton and Bobby Frank Cherry on eight counts each in relation to the 16th Street Baptist Church bombing.

In his opening statement to the jurors, defense attorney John Robbins acknowledged his client's affiliation with the Ku Klux Klan and his views on racial segregation.

Mauldin testified on April 30 that he had observed two men in a Rambler station wagon adorned with a Confederate flag repeatedly drive past the church immediately before the blast, and that, seconds after the bomb had exploded, the car had "burned rubber" as it drove away.

Stressing that Blanton should not be judged for his beliefs, Robbins again vehemently criticized the validity and poor quality of the audio recordings presented, and the selectivity of the sections which had been introduced into evidence.

Robbins also attempted to show that the testimony of FBI agent William Fleming, who had earlier testified as to a government witness claiming he had seen Blanton in the vicinity of the church shortly before the bombing, could have been mistaken.

Brogdon testified on May 16 that Cherry had boasted to her that he had been the individual who planted the bomb beneath the steps to the church, then returned hours later to light the fuse to the dynamite.

On May 15,[128] Cross testified that prior to the explosion, she and the four girls killed had each attended a Youth Day Sunday School lesson in which the theme taught was how to react to a physical injustice.

"[129] Cochran outlined Cherry's extensive record of racial violence dating back to the 1950s, and noted that he had experience and training in constructing and installing bombs from his service as a Marine demolition expert.

[130] In the closing argument for the defense, attorney Mickey Johnson argued that Cherry had nothing to do with the bombing, and reminded the jurors that his client was not on trial for his beliefs, stating: "It seems like more time has been spent here throwing around the n-word than proving what happened in September 1963.

On the afternoon of May 22, after the jury had deliberated for almost seven hours, the forewoman announced they had reached their verdicts: Bobby Frank Cherry was convicted of four counts of first-degree murder and sentenced to life imprisonment.

[131] Following the convictions of Blanton and Cherry, Alabama's former Attorney General, William Baxley, expressed his frustration that he had never been informed of the existence of the FBI audio recordings before they were introduced in the 2001 and 2002 trials.

Baxley acknowledged that typical juries in 1960s Alabama would have likely leaned in favor of both defendants, even if these recordings had been presented as evidence,[133] but said that he could have prosecuted Thomas Blanton and Bobby Cherry in 1977 if he had been granted access to these tapes.

[136] Investigative records show that Rowe had twice failed polygraph tests when questioned as to his possible involvement in the 16th Street Baptist Church bombing and two separate, non-fatal explosions.

Although never formally named as one of the conspirators by the FBI, Rowe's record of deception on the polygraph tests leaves open the possibility that Chambliss's claims may have held a degree of truth.