Twenty years ago today, two bearded men claiming to be prophets muscled their way into an American Fork duplex thirsting for blood.

When they left, their brother's wife and infant daughter lay dead, one on the kitchen floor, the other in her crib.

On the quiet street where the murders occurred, the crime is all but forgotten. Families have come and gone. Trees have grown tall. The Lafferty name is met with blank stares.

But some still remember Brenda and Erica Lafferty and the events of Pioneer Day 1984. The people have tried to bury memories of that day, but they keep coming back, like a wound that won't heal.

"I don't think I'll ever forget," says one neighbor. "My blood ran cold that day."

They were senseless murders — fueled by religious fanaticism, delusions of grandeur, and an upbringing warped by violence. There have been only a handful of capital murder cases in Utah County since.

"I'm sure the old-time residents remember," says American Fork Police Chief Terry Fox, who investigated the scene. "It's one of those threshold events that people just don't forget."

In the end, the killings of Brenda and Erica Lafferty were brutal crimes that scattered an unusually close-knit family, drove others into hiding, and deeply scarred those left in their wake.

"It damaged so many people's lives," says Kathy Pace, a former neighbor of Brenda Lafferty. "It's amazing how many people it hurt."

Seeds of madness

Ron and Dan Lafferty grew up in Payson, in a family of six boys and two girls. Their father, a stern disciplinarian, seethed with a quiet rage he sometimes directed toward his wife and pets. After one spat with his wife, he beat the family dog to death with a baseball bat.

In his sons, Watson Lafferty planted the seeds of paranoia, rebellion and fanaticism. He taught his boys to distrust conventional medicine and the federal government. He also took his religious beliefs to the extreme: When one son accidentally shot himself in the stomach with an arrow, he told him he would have to suffer until morning for breaking the Sabbath.

Ron and Dan became best friends, boys known for their short tempers and willingness to back each other in a fight. As they grew into men they took after their father in other ways, too. Instead of buying baby food, Dan chewed food into a mush and then spit it into the mouths of his children. He later refused to pay taxes or obey traffic laws, believing he was above the laws of man.

In 1982, the LDS Church excommunicated Dan for trying to take his 14-year-old stepdaughter as a second wife. Dan told his brothers they were the true leaders of God's church, and they believed him — letting their beards and hair grow long like Biblical prophets. The six boys were now spending more time with their brothers — railing against the LDS Church and the U.S. government — than they were with their own wives and children.