Alvin Lee Sykes was born on July 21, 1956, in Kansas City, Kan. He said that his father, Vernon Evans, had raped his mother, Patricia Sykes, who was 14 years old when she gave birth to him. Eight days later an acquaintance of his mother, Burnetta F. Page, took him in as a foster child.
He is survived by Edna Dill, his foster sister.
Mr. Sykes had a painful childhood. He suffered from epilepsy and mental illness and was in and out of the hospital. Two of his neighbors, he said, both adults, sexually assaulted him, twice. Ms. Page had to mortgage her house to cover his medical bills, and she later sent him to live in Boys Town, the home for at-risk youth outside Omaha.
When he returned he lived for a year with his birth mother and then with an uncle. Though he promised his uncle he would stay in school, he left after eighth grade, and to bide his time during the day he visited the public library’s main branch in Kansas City, Mo.
“There was a time when somebody like me wouldn’t have been allowed inside a library — or as a Black man permitted to read at all,” he told the journalist Monroe Dodd, the author of a short biography about Mr. Sykes. “But I was able to revolve much of my life around the library. I sought and got my education there.”
In 2013, the library named him its first scholar in residence.
Mr. Sykes joined the Marines in 1974, and when he left a year later he became the manager for a Kansas City funk band, Threatening Weather. He spent several years working in and around the city’s music scene and met the jazz pianist Herbie Hancock. The two became friends, and Mr. Hancock, a Buddhist, persuaded Mr. Sykes to convert.
His success in the Harvey case made Mr. Sykes famous around Kansas City as a tireless advocate for victims of injustices large and small, from murder to the denial of food stamps. Nor did he limit his activism to civil rights: He persuaded his friend, State Senator Haley, to sponsor a bill making extreme cruelty to animals a felony.
Some of his positions were seemingly at odds with his civil rights record. In the late 1980s Mr. Sykes and Mr. Haley supported an application by the Ku Klux Klan for airtime on a Kansas City public access TV station. Mr. Sykes defended their right to free speech, but also said that letting them air their racist views would turn off more people than attract them. He was right: The show drew few viewers and ended within a few months.