William Ernest Downs Jr. was born on July 12, 1967, in Augusta, Georgia. Before his arrest, he lived in Georgia and worked as a plumbing company employee. He was married and had a son. On the surface, Downs appeared to lead a regular life as a family man and a working professional. However, beneath that normal façade, he was hiding a dark and violent side.

In 1991, Downs committed his first known murder, of 10-year-old James Mitchell Porter, a boy from Augusta, Georgia. At the time, the case was misclassified as an accidental drowning due to the state of decomposition. Downs would later confess to kidnapping, raping, and murdering Porter, and he admitted to killing another unidentified 8-year-old boy in Augusta that same year in a similar manner. These crimes went undetected for nearly a decade until Downs finally confessed during questioning for another heinous act that would expose his true nature.

On April 17, 1999, six-year-old Keenan Andre O'Mailia was riding his bicycle in a park near his home in North Augusta, South Carolina, while his mother was cooking dinner. William Ernest Downs Jr. approached the child, asked for his name, then violently threw him to the ground and dragged him into a wooded area. There, he raped and strangled the boy to death before fleeing back to Georgia.

Keenan’s body was discovered the next day, sparking a massive investigation. Forensic evidence, including DNA, and Downs's eventual confession linked him to the crime. He was arrested on April 26, 1999, and during interrogation, he not only admitted to O'Mailia’s murder but also confessed to two more killings: 10-year-old James Porter and another unnamed 8-year-old boy, both from Augusta and murdered in 1991.

In South Carolina, Downs pleaded guilty on June 13, 2002, to murdering O'Mailia and openly requested the death penalty. The court obliged, and on June 27, 2002, he was sentenced to death by Judge Casey Manning.

A year later, Georgia authorities prosecuted Downs for the 1991 murder of James Porter. Though he initially pleaded not guilty, he eventually reached a plea deal on June 15, 2005, avoiding the death penalty in exchange for two consecutive life sentences plus ten years. This agreement ensured that even if his South Carolina sentence was overturned, he would never be released.

Downs declined to appeal his death sentence. After a mandatory mental competency hearing confirmed he was fit to waive further appeals, the South Carolina Supreme Court signed his death warrant in June 2006.

On July 14, 2006, Downs was executed by lethal injection at Broad River Correctional Institution. He offered no final words and died at 6:17 PM. For his last meal, he requested salted cashew nuts, instant french roast coffee, chocolate chip cookie dough, moose tracks ice cream, and three Mr. Goodbar candy bars.

Downs was one of the very few White inmates in modern U.S. history to be executed for the murder of African-American victims. His execution was the 36th in South Carolina since capital punishment resumed in 1985 and one of the rare instances where a White-on-Black crime led to the death penalty.