Robert William Fisher was born on April 13, 1961, in Brooklyn, New York City. His father, William Fisher, worked as a banker, and his mother, Jan Howell, was a homemaker. He was the middle child in the family, with one brother and one sister. When Robert was 15 years old, his parents divorced in 1976, and he moved with his sisters to live with their father in Arizona. All three siblings attended Sahuaro High School in Tucson, Arizona. The divorce was said to be very turbulent and had a lasting impact on Robert. A high school friend mentioned that Robert was "very bitter" about his parents' separation.

After finishing high school, Robert Fisher joined the United States Navy. He tried to become a member of the elite Navy SEALs, but he was not able to succeed. Following his time in the Navy, he worked as a firefighter in California until he had to retire due to a back injury. He then returned to Arizona, where he transitioned into the medical field. Robert worked as a surgical catheter technician and as a respiratory therapist.

In 1987, Fisher married Mary Cooper. The couple had two children together: a daughter named Brittney and a son named Bobby. Friends and family described Robert as controlling and cruel, especially towards his family. He and Mary argued frequently about various issues. Mary took a job to contribute to the family finances, which Robert did not support.

Robert's behavior towards his children was also concerning. He was embarrassed that his son Bobby did not want to hunt or fish. He once tried to teach both children how to swim by throwing them off a boat, which terrified them.

Though he presented himself as a devoted family man, he exhibited controlling behaviors in the home, such as restricting the colors of the walls and the number of pictures displayed. His behavior echoed the dynamics he experienced during his own childhood, particularly his feelings about his parents' divorce.

Fisher was known for his love of the outdoors. He enjoyed hunting and fishing. Friends described some of his actions during these activities as troubling. There were instances where he behaved violently or disturbingly, such as smearing the blood of an elk on his face after a hunt.

In the years leading up to significant events in his life, Fisher was becoming withdrawn, especially from the church activities he once participated in. His marriage was not happy, and Mary confided to friends that she planned to divorce him.

On April 10, 2001, Robert William Fisher's family home in Scottsdale, Arizona, exploded. This explosion happened at 8:42 AM and was so powerful that it collapsed the front brick wall of the house and shook nearby homes. Firefighters arrived quickly, but before they could control the flames, neighbors tried to put out the fire using garden hoses. They noticed that smaller explosions were occurring, likely due to ammunition or paint cans inside the house.

Inside the ruins, firefighters found the bodies of Fisher's wife, Mary, and their two children, Brittney, age 12, and Bobby, age 10. Mary had been shot in the back of the head, while Brittney and Bobby's throats had been slashed. Investigators believe that the murders took place the night before, between 9:30 PM and 10:15 PM. The night before the explosion, a neighbor heard a loud argument coming from the house around 10 PM.

Police investigated the scene and found that the gas line had been pulled from the furnace. It was believed that Fisher lit a candle to allow gas to accumulate in the house, which later ignited, causing the explosion. This method likely gave him a significant head start before law enforcement began the search for him.

Fisher was named as the prime suspect in the case on April 14, 2001, just days after the explosion. He had disappeared, and police believed he fled in his wife’s car, a Toyota 4Runner that was found abandoned a few days later in the Tonto National Forest, about one hundred miles away. The family dog was found nearby, suggesting Fisher may have stayed in the area for some time.

The investigation unfolded as police followed various leads, but many of these turned out to be false or inconclusive. Fisher was added to the FBI's Ten Most Wanted list on June 29, 2002. In the years following, sightings of him were reported in various locations, but none could be confirmed. Despite extensive searches and numerous tips, no trace of Fisher has ever been found.

Over time, various theories emerged about his fate. Some suggested he may have died in the wilderness where his car was found, while others believed he could have started a new life under a different identity. As the investigation continued for years, there was no conclusive evidence to resolve the case. Fisher remains a fugitive, and the details of the events of that April night cause ongoing speculation.