Lee has said that To Kill a Mockingbird is not an autobiography, but rather an example of how an author "should write about what he knows and write truthfully". Nevertheless, several people and events from Lee's childhood parallel those of the fictional Scout. Lee's father, Amasa Coleman Lee, was an attorney, similar to Atticus Finch, and in 1919, he defended two black men accused of murder. After they were convicted, hanged and mutilated, he never tried another criminal case. Lee's father was also the editor and publisher of the Monroeville newspaper. Although more of a proponent of racial segregation than Atticus, he gradually became more liberal in his later years. Though Scout's mother died when she was a baby, Lee was 25 when her mother, Frances Cunningham Finch, died. Lee's mother was prone to a nervous condition that rendered her mentally and emotionally absent. Lee had a brother named Edwin, who—like the fictional Jem—was four years older than his sister. As in the novel, a black housekeeper came daily to care for the Lee house and family.
Lee modeled the character of Dill on her childhood friend, Truman Capote, known then as Truman Persons. Just as Dill lived next door to Scout during the summer, Capote lived next door to Lee with his aunts while his mother visited New York City. Like Dill, Capote had an impressive imagination and a gift for fascinating stories. Both Lee and Capote were atypical children: both loved to read. Lee was a scrappy tomboy who was quick to fight, but Capote was ridiculed for his advanced vocabulary and lisp. She and Capote made up and acted out stories they wrote on an old Underwood typewriter Lee's father gave them. They became good friends when both felt alienated from their peers; Capote called the two of them "apart people". In 1960, Capote and Lee traveled to Kansas together to investigate the multiple murders that were the basis for Capote's nonfiction novel In Cold Blood.
Down the street from the Lees lived a family whose house was always boarded up; they served as the models for the fictional Radleys. The son of the family got into some legal trouble and the father kept him at home for 24 years out of shame. He was hidden until virtually forgotten; he died in 1952.
The origin of Tom Robinson is less clear, although many have speculated that his character was inspired by several models. When Lee was 10 years old, a white woman near Monroeville accused a black man named Walter Lett of raping her. The story and the trial were covered by her father's newspaper which reported that Lett was convicted and sentenced to death. After a series of letters appeared claiming Lett had been falsely accused, his sentence was commuted to life in prison. He died there of tuberculosis in 1937. Scholars believe that Robinson's difficulties reflect the notorious case of the Scottsboro Boys, in which nine black men were convicted of raping two white women on negligible evidence. However, in 2005, Lee stated that she had in mind something less sensational, although the Scottsboro case served "the same purpose" to display Southern prejudices. Emmett Till, a black teenager who was murdered for flirting with a white woman in Mississippi in 1955, and whose death is credited as a catalyst for the Civil Rights Movement, is also considered a model for Tom Robinson.