Zane Michael Floyd was born on September 20, 1975, in Nevada, USA. He grew up in a family that faced challenges. Information about his early childhood and family life is limited. However, it is known that he attended Faith Lutheran Middle School and High School. After graduating from high school, Zane Floyd joined the United States Marine Corps.

Floyd served in the Marines and was honorably discharged in 1998. His discharge was due to issues related to heavy drinking. After leaving the military, Floyd faced difficulties in his personal life. He worked as a security guard and also as a bouncer in a bar. Unfortunately, days before a significant event in his life, he was fired from his job as a security officer and had to move back in with his parents after losing his apartment.

During the penalty phase of his trial, it was suggested that he might have suffered from fetal alcohol syndrome. This condition can happen when a mother drinks alcohol during pregnancy, affecting the child’s development.

On June 3, 1999, around 5:15 in the morning, Zane Michael Floyd entered an Albertson's supermarket in Las Vegas with a shotgun. He began shooting at random people inside the store. His first victim was 40-year-old Thomas Darnell, who was shot in the back and died. Floyd then killed 41-year-old store manager Carlos Chuck Leos and 31-year-old employee Dennis Troy Sargent.

Next, Floyd encountered 23-year-old Zachary T. Emenegger. When Emenegger saw the gun, he ran and dove under a produce table. He managed to avoid Floyd's shots for about 15 seconds but was ultimately hit in the upper chest, which punctured his lung. Floyd shot Emenegger again, but believing him to be dead, moved on. After that, he shot 60-year-old clerk Lucille Alice Tarantino in the head at close range.

After the shooting, Floyd exited through the supermarket's north doors, where the police had been alerted to a robbery. When he realized that the police were surrounding the area, he ran back inside and threatened to kill himself. After an eight-minute standoff with the police, he surrendered without further violence. Floyd was arrested and later confessed to the murders, stating that he had always wanted to know what it felt like to kill someone.

During the trial, jurors saw his confession and video evidence from the store's surveillance cameras. They convicted him of multiple counts of first-degree murder and other serious offenses. On July 13, 2000, the jury sentenced Floyd to death.

Floyd appealed his conviction several times, but each time his appeals were denied. In 2021, the State of Nevada began the process to carry out his execution. His execution was scheduled for July 26, 2021, but it was stayed by a federal judge due to legal challenges related to the execution protocol. As of July 2023, Floyd still has pending petitions in court regarding his execution.