William Henry Theodore Durrant was born on April 28, 1871, in Toronto, Ontario, Canada, to William Durrant, a shoemaker, and Isabella Hutchenson Durrant. In 1879, the family immigrated to San Francisco, California. Durrant had a younger sister, Beulah Maud Durrant, who later gained fame as the stage dancer Maud Allan.

Durrant was an intelligent and ambitious young man. He enrolled at Cooper Medical College in San Francisco, aspiring to become a physician. Concurrently, he served as the assistant superintendent of the Sunday School at Emmanuel Baptist Church and was a member of the California Signal Corps. Despite his outward piety and dedication, there were rumors about his erratic behavior and dark proclivities. Some accounts suggested he suffered from manic depression, and there were unsubstantiated claims that he engaged in disturbing acts, such as visiting brothels and exhibiting violent tendencies towards animals.

In the spring of 1895, San Francisco was shaken by two gruesome murders linked to Emmanuel Baptist Church.

Blanche Lamont, a 20-year-old teacher from Montana, disappeared on April 3, 1895. Witnesses saw her entering the church with Durrant that afternoon. She was never seen alive again. Durrant later visited her aunt, expressing concern and suggesting that Blanche might have eloped or been kidnapped. Days later, he attempted to pawn some of Blanche's jewelry, raising suspicions.

Minnie Williams, a 21-year-old congregant, was last seen on April 12, 1895, arguing with Durrant outside the church. Witnesses reported seeing them enter the building together. The next day, her mutilated body was discovered in a church closet by members preparing for Easter services. This discovery prompted a thorough search of the church, leading to the grim finding of Blanche Lamont's decomposed body in the belfry. Both women had been strangled, and Blanche's body was posed in a manner reminiscent of medical cadavers, suggesting a macabre connection to Durrant's medical studies.

Durrant was arrested on April 14, 1895, while attending a meeting of the Signal Corps. The trial commenced on July 22, 1895, and garnered national attention. The prosecution presented compelling evidence, including eyewitness testimonies and the pawned jewelry. Despite the defense's attempts to cast doubt, the jury found Durrant guilty of Blanche Lamont's murder on November 1, 1895. He was sentenced to death.

After numerous appeals, including to the U.S. Supreme Court, Durrant was executed by hanging at San Quentin State Prison on January 7, 1898. He maintained his innocence until the end, refusing to confess to the crimes. His body was cremated in Los Angeles, as no San Francisco crematory would accept it due to public sentiment.