An animal trainer who came from a long line of circus performers remained in critical condition with severe head wounds Thursday after a tiger he had raised from infancy bit his head and refused to let go.

The trainer's brother shot and killed the 350-pound tiger after the attack Wednesday.Richard Chipperfield, 24, was attacked while a dozen tigers were inside a ring for a Ringling Bros. and Barnum & Bailey circus practice and promotional photo shoot, police spokesman Bill Doniel said.

"At the end of the act, Richard goes face to face with one of the tigers as if he is about to kiss it," Ringling Bros. spokeswoman Laura Fitzgerald told the British news agency Press Association.

"As he did that another tiger, a 4-year-old Bengal called Arnie, attacked him from behind, biting the back of his head," she said. "Arnie was a tiger that Richard had raised from infancy, so he knew him very well."

Chipperfield yelled, and two other trainers, including his brother, grabbed fire extinguishers and fired at the tiger, Doniel said. The animal loosened his grip, allowing the trainers to pull Chipperfield away.

The tigers were returned to their cages, and Graham Thomas Chipperfield shot Arnie five times with a 12-gauge shotgun, Doniel said.

"He felt there was potential danger," Doniel said. "That's in addition to the emotion that was caused by seeing his brother attacked, lying on the ground, with severe head wounds, bleeding."

Police were investigating whether Graham Chipperfield violated state laws against animal cruelty and discharging a firearm in a public building, Doniel said.

The Wednesday evening performance of the circus went on as planned, but the tiger act was omitted.

Members of the Chipperfield family have been performing with circuses since 1684, Ringling Bros. spokesman Rodney Huey said.

Richard Chipperfield began learning to be an animal trainer at age 4, working with 3-month-old tiger cubs. He made his American debut with the touring circus on Dec. 27.