Prosecutors have also filed a new enhancement against 52-year-old Steven Hayashi alleging child abuse with willful harm or injury resulting in death, to which he also pleaded not guilty. The charge alleges that Hayashi allowed his step-grandson, Jacob Bisbee, to be in a situation that resulted in his death.
According to Deputy District Attorney Mary Knox, if he is convicted of all the charges, Hayashi could face a maximum state prison sentence of 10 years.
On the morning of the attack, Hayashi allegedly left his house at 1785 Trailcreek Court to go play tennis with his 13-year-old son.
The door to the garage where three of his five pit bulls were being kept was usually locked with a deadbolt, but Hayashi allegedly left without locking it. He also allegedly left without waking up his wife, Knox said.
At about 8:45 a.m., Jacob went into the garage and was attacked by the three dogs inside. The two other dogs were in the yard at the time and were not part of the attack.
Jacob was taken by ambulance to John Muir Medical Center in Walnut Creek, where he was pronounced dead.
An autopsy found that he died from skull fractures and severe bleeding from multiple dog bites, according to the Contra Costa County coroner's office.
In a jailhouse interview the day after the attack, Hayashi admitted that he knew one of his dogs, "Kiwi", was aggressive and said that the dogs had killed a pet Chihuahua about a year ago.
Knox, however, said today that the dogs had also killed an Akita - a large dog that can weigh 70 to 100 pounds - as well as a pet parrot, and had showed previous signs of aggression toward Jacob and his 4-year-old brother.
Jacob, his brother and their father had come to live with Hayashi and his family about a year ago, Hayashi said. At that time, he said, his wife had asked him to get rid of the dogs because it wasn't safe for the children, but he said he loved the dogs and didn't have the heart to have them put down.
"I am not one of those people who breeds dogs for fighting or for a pack," Hayashi said. "These are supposed to be house pets."
He also said, however, that he didn't trust Kiwi and never let him around the children. He admitted that the dog had showed previous signs of aggression.
Contra Costa Animal Services officers seized all five dogs after the attack and destroyed them, Hayashi said.
Hayashi posted bail on Wednesday and was out of custody today, but prosecutors are seeking to increase his bail in light of the new enhancement. He is scheduled to return to Contra Costa County Superior Court in Martinez on Monday for a bail hearing.