SCOTTSDALE, AZ — Now two decades later, one of Arizona's most infamous cases still brings in tips, while leaving friends and investigators split on what happened to the man at the center of the mystery.
Robert Fisher, who would turn 60 this month, is accused of murdering his wife and two children and blowing up their Scottsdale home in 2001. To this day he has never been found and is a mainstay on the FBI's Ten Most Wanted list.
"This is, by far, the most heinous crime that we've had here in Scottsdale," said Scottsdale Police Detective John Heinzelman.
Heinzelman has been assigned the Robert Fisher case for the past five years and said tips still come in to this day.
"We still get tips on a weekly basis, if not daily basis," Heinzelman said. "The tips we get vary from any number of things, it could be something as simple as, 'I was looking at Facebook and I saw a person named Bob or Robert Fisher."
To this day, what happened to Fisher remains a mystery. His Scottsdale home exploded on April 10, 2001. Investigators later found the bodies of his wife, Mary, and two children, Brittney, 12, and Bobby, 10 inside the home.
"They died brutally," Heinzelman said. "Mary was shot and her throat was cut, and both Bobby and Brittney had their throats slashed, almost from ear to ear."
Authorities determined a gas line to the home had been severed and the house rigged to explode.
Robert Fisher was not found at the scene, but was spotted on an ATM camera withdrawing $280 the night before the fire.
"I think blowing up the house was purely a delay tactic, a discovery tactic, he knew that the bodies were going to be found," Heinzelman said. "Maybe in his thought, if the entire house is incinerated maybe it's believed that he perished in the fire along with his family. Maybe it's purely an evidence eradication."
Mary's 4Runner, along with the family dog, were found 10 days later in the woods near Payson. Fisher was nowhere to be found. Heinzelman noted that the area is extremely remote and has a lot of caves.
"The other part to that is, it is less than a mile away from the Apache Indian Reservation," he said. "That is a sovereign nation that we don't travel onto."
According to the Scottsdale police report, Fisher had previously enlisted in the U.S. Navy but failed in his attempt to become a Navy SEAL and was described as an outdoorsman.
Heinzelman told ABC15 Fisher is the lone suspect in the murders.
While no official motive for the murders, friends and investigators have described Mary and Robert's marriage as one that had problems, and Fisher had taken issue with his own parents' divorce. That, according to police, is one theory.
"The fear that we believe he had of being divorced was very strong," Heinzelman said. "He's in despair, he's in his lowest moment, he's afraid that Mary's going to divorce him and he's going to lose his children."
A Scottsdale police report spans more than 400 pages and details odd behavior from Fisher throughout his life, in interviews with friends and coworkers. According to the report, Fisher would randomly shoot his gun in the air when on a hunting trip with friends and was also seen in a photograph covered in animal blood standing next to a deer he killed.
"As an investigator, we want all the puzzle pieces, we want to see what the picture looks like at the end," Heinzelman said. "Right now, there's a gap, we're missing some pieces."
According to the police report, roughly two years before the fire, Fisher admitted to an affair. Mary kicked him out of the house, but the two eventually reconciled and continued their rocky relationship, according to the police report.
The police report also notes Fisher's behavior changed two months prior to the fire, as he stopped working out at his gym and dropped out of a men's group at his church.
Investigators have received tips and unconfirmed sightings of Fisher over the years. However, Heinzelman told ABC15 the last confirmed sighting is when Fisher appeared on the ATM camera the night prior to the fire.
"That's the last piece of information that we had or that first bread crumb as I would call it, to say here's where we can positively say he was here at this date, at this time," Heinzelman said. "The rest of it has been the greatest mystery that we've had."
Depending on who you ask, you will get different theories as to what happened to Robert Fisher. Did he take his own life and his body was never found in the woods? Or, did he manage to move on and is alive, living under an alias somewhere in the world today?
A former neighbor and former investigator told ABC15 they believe Fisher is still alive.
Heinzelman believes the opposite.
"I'm leaning toward the fact that he is not [alive]," he said. "Only so much as to say that we've never had one verified sighting. It does make sense that a person that would be driven to commit the crimes that he committed, I can't fathom how he could go on living."
ABC15 asked Heinzelman what he would say to Fisher if he happens to still be alive today.
"I would say it's been long enough," Heinzelman said. "He needs to come in."
The FBI is offering a reward of up to $100,000 in the case.