In 1965, he was killed by Tom Coleman, a highway worker and part-time deputy sheriff, in Hayneville, Alabama, while in the act of shielding 17-year-old Ruby Sales from a racist attack.

Daniels considered a career in the ministry as early as high school and joined the Episcopal Church as a young man.

He began to question his religious faith during his sophomore year, possibly because his father died and his sister Emily suffered an extended illness at the same time.

In the spring of 1962, during an Easter service at the Church of the Advent in Boston, Daniels felt a renewed conviction that he was being called to serve God.

After a working out of family financial problems, he applied and was accepted to the Episcopal Theological School in Cambridge, Massachusetts, starting his studies in 1963 and expecting to graduate in 1966.

On August 14, 1965, Daniels was one of a group of 29 protesters, including members of the Student Nonviolent Coordinating Committee (SNCC), who went to Fort Deposit, Alabama, to picket its whites-only stores.

Daniels and three others—a white Catholic priest and two black female activists—walked to buy a cold soft drink at nearby Varner's Cash Store, one of the few local places to serve non-whites.

But barring the front was Tom L. Coleman, an unpaid special deputy who was holding a shotgun and had a pistol in a holster.

Richmond Flowers Sr., the Attorney General of Alabama, believed the charge should have been murder and intervened in the prosecution, but was thwarted by the trial judge T. Werth Thagard.

Flowers described the verdict as representing the "democratic process going down the drain of irrationality, bigotry and improper law enforcement.

She worked as a human rights advocate in Washington, DC, and founded an inner-city mission dedicated to Daniels.