Important dates in the investigation of the 1963 bombing of the Sixteenth Street Baptist Church in Birmingham, Ala.:

-- Sept. 15, 1963: Dynamite bomb explodes outside Sunday services at Sixteenth Street Baptist Church, killing 11-year-old Denise McNair and 14-year-olds Cynthia Wesley, Carole Robertson and Addie Mae Collins, and injuring 20 others.

-- May 13, 1965: FBI memorandum to director J. Edgar Hoover concludes the bombing was the work of former Ku Klux Klansmen Robert E. Chambliss, Bobby Frank Cherry, Herman Frank Cash and Thomas E. Blanton, Jr.

-- 1968: FBI closes its investigation without filing charges.

-- 1971: Alabama Attorney General Bill Baxley reopens investigation.

-- Nov. 18, 1977: Chambliss convicted on a state murder charge and sentenced to life in prison.

-- 1980: Justice Department report concludes Hoover had blocked prosecution of the Klansmen in 1965.

-- Oct. 29, 1985: Chambliss dies in prison, still professing his innocence.

-- 1988: Alabama Attorney General Don Siegelman reopens the case, which is closed without action.

-- 1993: Birmingham-area black leaders meet with FBI, agents secretly begin new review of case.

-- Feb. 7, 1994: Cash dies.

-- July 1997: Cherry interrogated in Texas; FBI investigation becomes public knowledge.

-- Oct. 27, 1998: Federal grand jury in Alabama begins hearing evidence.

-- May 17, 2000: Blanton and Cherry surrender on murder indictments returned by grand jury in Birmingham.

-- April 10, 2001: Judge delays Cherry trial, citing defendant's medical problems amid questions over his mental competency.

-- May 1, 2001: Blanton convicted of murder and sentenced to life in prison.