LOS ANGELES -- Bill Kuenzi was visiting a friend in San Francisco's posh Pacific Heights neighborhood on the afternoon of Jan. 26, 2001. He was unlocking his friend's third-story apartment door when he heard a woman begin to scream.

"It was high-pitched, desperate, continuous screaming," Kuenzi testified in Superior Court in Los Angeles early this year, "of a woman who was obviously being attacked. I knew I had to do something and I tried to call 911 on my cell phone."

Kuenzi's phone didn't work where he was. So he went to the stairs for better reception and began climbing toward the screaming. The cell phone still didn't work.

Kuenzi continued until he reached the fifth floor. Then fear stopped him. The screaming was coming from the sixth floor.

"I assumed it was a domestic violence situation," said Kuenzi, a 35-year-old stockbroker. "Or a woman being sexually assaulted. I realized that when I climbed to the sixth floor landing, I would be exposed to the situation, which I knew was violent, and I was scared."

He had good reason. The violence that Kuenzi feared was not being perpetrated by some enraged boyfriend who might be calmed down, or even a rapist who could be scared off by the arrival of other people.

The attack taking place a floor above Kuenzi was being carried out by two huge Canary Island mastiffs bred as vicious attack dogs by a pair of prison cellmates who belong to the white supremacist Aryan Brotherhood — possibly the most frightening race-based prison gang in this country.

The dogs were mauling to death Diane Whipple, a petite 34-year-old college lacrosse coach and resident of the sixth floor.

Descending again, Kuenzi finally got through to police. As he reached the ground floor, he heard Whipple's cries change to a low moan.

"Then the screaming stopped," he said.

Known as Presa Canarios, the dogs belonged to Whipple's neighbors, Robert Noel and Marjorie Knoller, husband-and-wife attorneys whose practice had put them in contact with the two life-term prisoners at Pelican Bay, the most secure facility in the California system.

With Noel and Knoller's help, Paul "Cornfed" Schneider and Dale Bretches were running a dangerous business — against prison rules that outlaw such long-distance entrepreneurship — that they called Dog o' War.

Officials believe that huge dogs were being raised for sale to guard methamphetamine labs.

Noel, 60, and Knoller, 46, were convicted here in late March of involuntary manslaughter and, in Knoller's case, second-degree murder as well. They face sentences of up to four years and 15 years, respectively, for their roles in Whipple's death.

These were hardly your run-of-the-mill Aryan Brotherhood associates. Noel is a former federal prosecutor, and both attorneys had a fondness for the opera and causes like helping the homeless and the mentally ill.

But in the days following Whipple's death, both made grotesque comments that essentially blamed the victim for her own death. For them, it seemed clear, Whipple's savaging was, at worst, an inconvenience and annoying public relations problem.

Beyond the issue of criminal liability for the dogs' behavior lies the deeper puzzle that seems beyond logical explanation:

What was the Aryan Brotherhood doing in the latte-and-Pellegrino realm of Noel and Knoller's toney Pacific Heights neighborhood? What possible explanation was there for the couple's transformation from socially aware attorneys into apparently depraved human beings?

Those questions may never be fully answered. But the circumstances of Whipple's death and the events leading up to it — including the attorneys' illicit ties to the Aryan Brotherhood — make it clear that Noel and Knoller's descent into darkness involved the age-old attractions of power, violence and forbidden sex.

'Afraid for our Lives'
The bloodshed that Schneider and Bretches' Dog o' War business visited upon an upscale apartment building in San Francisco was beyond the emotional and professional scope of the emergency workers who responded.

The first police officers at the scene found Whipple in the sixth-floor hallway, nude, mutilated, covered in blood, and trying to crawl to her open apartment door.

On the witness stand in the Knoller-Noel trial, veteran officers said they radioed for backup before giving Whipple first aid.

"We were afraid for our lives," Patrol Sgt. Lesley Forrestal explained. "We saw what the dogs had done to her and we didn't know whether we would be attacked, too. I radioed that I was going to shoot on sight."

Whipple was beyond help. Her larynx was crushed and her jugular vein had been severed by dog bites. She would die in the emergency room 70 minutes after the attack.

Meanwhile, as more police and paramedics arrived minutes after Forrestal's call, Marjorie Knoller emerged from her apartment down the hall, her sweatshirt bloodied, blood on her hair and face, and small cuts on two fingers of one hand that she claimed she had suffered in trying to stop the fatal attack.

Knoller, a small woman, usually did not try to manage both dogs herself because Bane, the 140-pound male, substantially outweighed her. Hera, the 115-pound female, was plenty.

On the day of Whipple's death, Knoller says she took both dogs out because Noel was away. When she opened her apartment door, Bane supposedly bolted in a mad rush for Whipple, dragging Knoller after him down the hall toward Whipple, who just had time to unlock her door and set one grocery bag down inside her apartment.

Then, in a scene that suggested a horror movie, Bane mauled Whipple from head to toe while Hera ripped off her clothing.

Michael Scott was the second animal control officer to arrive at the scene.

"I was told that the bigger of the two dogs — Bane — was in the bathroom," he testified. "I could hear him, panting, snarling and pacing behind the bathroom door. The bathroom door was being covered by a police officer with a machine gun, backed up by another officer with a drawn gun."

Two other officers stood with drawn guns guarding the door to the bedroom where Hera could be heard bashing the door from inside, so hard that Scott feared the door might give way.

Scott cracked the bathroom door and fired three tranquilizer darts at Bane, none of which had any effect. Then he attempted to remove Bane with a come-along, a device with a steel braid loop that functions as a rigid leash.

"When I tried to move the dog," Scott said, "he rushed me and almost knocked me off my feet. I was lucky I was wearing a bulletproof vest. It took all my strength to force him with the come-along away from the door opening and shut the door."

Scott waited until a third animal control officer arrived. Then the two of them were able to control Bane, using two come-alongs. He was quickly put to death.

If that had been all, as horrible as it was, that might have been the end of it. But lawyers Noel and Knoller could not seem to keep their mouths shut.