Travis the chimpanzee, a veteran of TV commercials, was the constant companion of a lonely Connecticut widow who fed him steak, lobster and ice cream. He could eat at the table, drink wine from a stemmed glass, use the toilet, and dress and bathe himself.
He brushed his teeth with a Water Pik, logged on to a computer to look at photos and channel-surfed television with the remote control.
But on Monday, the wild animal in him came out with a vengeance.
The 200-pound animal viciously mauled a friend of his owner before being shot to death by police.
Investigators are trying to figure out why - whether it was a bout of Lyme disease, a reaction to drugs, or a case of instinct taking over.
"It's hard to say what exactly precipitated this behavior," said Colleen McCann, a primatologist at the Bronx Zoo. "At the end of the day, they are not human and you can't always predict their behavior and how they or any other wild animal will respond when they feel threatened."
Travis attacked 55-year-old Charla Nash as Sandra Herold frantically stabbed her beloved pet with a butcher knife and pounded him with a shovel. Nash was in critical condition Tuesday with "life-changing, if not life-threatening," injuries to her face and hands, Mayor Dannel Malloy said.
Police said they are looking into the possibility of criminal charges. A pet owner can be held criminally responsible if he or she knew or should have known that an animal was a danger to others.
In recordings of calls to 911 dispatchers released Tuesday, Travis' grunts can be heard as a frantic Herold cries that her pet is "eating" Nash and must be killed. The attack lasted about 12 minutes.
"The chimp killed my friend!" says a sobbing Herold, who was hiding in her vehicle. "Send the police with a gun. With a gun!"
The dispatcher later asks, "Who's killing your friend?"
"My chimpanzee!" she cries. "He ripped her apart! Shoot him, shoot him!"
After police arrive, one officer radios back: "There's a man down. He doesn't look good," he says, referring to Nash. "We've got to get this guy out of here. He's got no face."
Police said that Travis was agitated earlier Monday and that Herold had given him the anti-anxiety drug Xanax in some tea. Police said the drug had not been prescribed for the 14-year-old chimp.
In humans, Xanax can cause memory loss, lack of coordination, reduced sex drive and other side effects. It can also lead to aggression in people who were unstable to begin with, said Dr. Emil Coccaro, chief of psychiatry at the University of Chicago Medical Center.
"Xanax could have made him worse," if human studies are any indication, Coccaro said.
Stephen Rene Tello, executive director of Primarily Primates, a sanctuary for chimps in Texas, said it is difficult to say what effect Xanax would have on a chimp, but he noted that chimps and humans have similar physiology.
Investigators said they were also told that Travis had Lyme disease, a tick-borne illness with flu-like symptoms that can lead to arthritis and meningitis in humans.
"Maybe from the medications he was out of sorts," Stamford police Capt. Richard Conklin said.
Herold could not be reached for comment. A woman answering the door at Herold's home, where drops of blood stained the walkway, would not speak to reporters Tuesday. Conklin said Herold was "traumatized by this very, very brutal attack."
Don Mecca, a family friend from Colchester, N.Y., said Herold, whose daughter died several years ago in a car accident, fed the chimp steak, lobster, ice cream and Italian food.
Herold built the chimpanzee a large cage in her home. She knew chimps could be dangerous but found it hard to part with Travis, Mecca said.
McCann of the Bronx Zoo said chimpanzees are unpredictable and dangerous even after living among humans for years.
"I don't know the effects of Lyme disease on chimpanzees, but I will say that it's deceiving to think that if any animal is, quote-unquote, well-behaved around humans that means there is no risk involved to humans for potential outbursts of behavior," she said. "They are unpredictable, and in instances like this you cannot control that behavior or prevent it from happening if it is in a private home."
Connecticut law requires anyone who owns a primate heavier than 50 pounds to obtain a state permit. But Herold was exempted from the law.
"Given that the family in Stamford owned Travis before this law was put on the books, and the fact that over the years the animal did not appear to present a public safety risk, their possession of the chimpanzee was allowed to continue," said Dennis Schain, spokesman for the state Department of Environmental Protection.
When he was younger, Travis starred in TV commercials for Old Navy and Coca-Cola, made an appearance on the "Maury Povich Show" and took part in a television pilot, according to a 2003 story in The Advocate newspaper of Stamford.
"He's been raised almost like a child by this family," Conklin said. "He rides in a car every day. He opens doors. He's a very unique animal in that aspect. We have no indication of what provoked this behavior at all."