Marjorie Knoller and her husband Robert Noel were both lawyers living in Pacific Heights, San Francisco. They were keeping two adult Presa Canario dogs for a client; the male, Bane, weighed 130 lb. Knoller and Noel had warnings from the dogs' veterinarian and a former caretaker of the dogs that they were dangerous, possibly should be put down, and were not suitable for an urban environment. There had also been numerous incidents where the dogs had attacked dogs and people, including their neighbor Diane Whipple, but the couple seemed amused by the incidents and sometimes dismissed them as playfulness, and failed to take safety measures such as muzzling the dogs. On January 26, 2001, Knoller and the dogs encountered Diane Whipple in the hall and Bane, and perhaps the female Hera, attacked her; she died later. Knoller and Noel expressed no remorse, and attempted to blame Whipple for the attack. Marjorie Knoller was found guilty of involuntary manslaughter, keeping a mischievous animal, and second-degree murder, the first person to be found guilty of murder for an animal attack.