SAN FRANCISCO -- The San Jose teenager who died in the Christmas Day fatal tiger attack at the San Francisco Zoo lured the big cat away from attacking his friend, San Francisco police chief Heather Fong said Thursday.

At a noon news conference, Fong gave an in-depth description of the attack as formulated by her investigators. She said the attack began with the tiger pouncing on one of two brothers who were visiting the zoo with their friend Carlos Sousa Jr.

"At the time of the attack, two of the people who were not attacked, yelled and tried to distract the tiger (from its attack on the third)," Fong said. "The tiger let go of the first victim and started to turn toward one of the other victims. The first victim and the brother saw the tiger grab onto the victim (Sousa) who died"

"The brothers then ran up (to the Terrace Cafe)… they had...bought some food at the Terrace Café (earlier in the day) so they knew people would be there."

The second attack took place about 300 yards away, in front of the zoo cafe. The police chief said the animal was mauling one of the survivors, and when officers yelled at it to stop, it turned toward them and they opened fire.

Fong said a forensic team would attempt to match a shoeprint found on the railing of the San Francisco Zoo tiger enclosure with shoes taken from the three victims of the fatal Christmas day attack to determine if the men were taunting the animal before it struck.

At the press conference, Fong knocked down a report in the San Francisco Chronicle that a shoe and blood had been found near or inside the tiger enclosure.

"We are analyzing the shoe print with the shoes we have recovered," she said. "We have no information to tell us at this point that they (the victims) did or did not go over the fence."

"There was no shoe found in the grotto (the enclosure) or in the foliage…Two victims had their shoes on…One victim -- the victim who was attacked at the Terrace Café -- had one off his shoes off but it was next to his person."

When asked earlier in the day, Sousa's father said he did not believe his son would have taunted the tiger.

"I don't think my son would do something like taunt animals," Carlos Sousa told ABC's "Good Morning America." "It's unbelievable, but only the evidence can prove that. And right now I can't say much…I don't think this deserves to happen to anybody -- taunting or not taunting."

"Animals should be protected from the people and the people should be protected from the animals."

Fong said Wednesday the department opened a criminal investigation to "determine if there was human involvement in the tiger getting out or if the tiger was able to get out on its own."

The zoo remained closed Thursday.

The two injured men, 19- and 23-year-old brothers from San Jose, were in stable condition Wednesday at San Francisco General Hospital. They suffered deep bites and claw wounds on their heads, necks, arms and hands, said Dr. Rochelle Dicker, a surgeon. She said they were expected to recover fully.

Sousa's parents told the AP they didn't know why their son went to the zoo Tuesday, but it should have been a fun Christmas Day activity.

"It's not a safe place for kids," said his mother, Marilza Sousa. "People go there to have a good time, not to get killed."