Briley Rex Piper was born on March 20, 1980, in the United States. Little is known about his early life, but by the late 1990s, Piper had developed a close association with Jeremy Page and Elijah Hoadley. The trio lived together in South Dakota and spent much of their time engaging in petty crime and substance abuse. Piper was described as charismatic and manipulative, traits that would later emerge during one of the most sadistic murders in South Dakota’s history.

In 2000, Piper’s life took a dark turn when he and his associates targeted Chester Allan Poage — a casual friend — in a plan that escalated from robbery to torture and murder. At only 20 years old, Piper would become one of the youngest people in South Dakota’s modern history to receive a death sentence.

On the evening of March 12, 2000, Chester Poage met with Briley Piper, Elijah Page, and Darrell Hoadley at Poage's home. They gathered to play video games while Poage's family was away on vacation. Later, the group left the house and drove to the residence where Piper, Page, and Hoadley were staying. Inside, they planned to rob Poage's family home. To do so, Page pulled out a stolen .22 caliber pistol and ordered Poage to get on the floor. Piper kicked Poage repeatedly until he lost consciousness. They tied him up and forced him to drink beer mixed with crushed pills and hydrochloric acid.

After this, the group took Poage in his own vehicle and drove him to Higgins Gulch, a remote area in the Black Hills. They stripped him down, apart from his undershirt, shoes, and socks. While walking him to a small icy creek, they beat him. Once at the creek, they attacked him further and Page stabbed him in the neck. The three men discussed killing Poage because they did not want him to be a witness to their crime. Poage pleaded to be let into the vehicle to warm up but had to wash the blood off himself first.

While he did this, Piper changed his mind and helped drag Poage back into the creek as they attempted to drown him. Ultimately, Poage was killed by rocks thrown at his head. After beating him, the group left his body in the creek. They then returned to Poage's house to steal items before leaving South Dakota to evade capture.

On April 22, 2000, Poage's remains were discovered in Higgins Gulch. An investigation led to Hoadley confessing to his involvement and naming Piper and Page as his accomplices. The authorities tracked and arrested Page in Texas and Piper in Alaska. They were extradited back to South Dakota and later pleaded guilty to first-degree murder. Both received death sentences, while Hoadley was given life imprisonment.