Story highlights Richard White, 49, of San Diego, California, was hiking alone when the bear killed him

Photos taken by the backpacker just before the attack show "nothing graphic," a park spokeswoman says

"We're not sure what happened after the camera was put down," she says

State troopers and rangers killed the bear Saturday

A southern California man killed by a grizzly bear in Alaska's backcountry was shooting photos of the animal that killed him just moments before the attack, a National Park Service official said Sunday.

The bear that killed Richard White, 49, was still with his body when rangers found him in Denali National Park on Saturday, the official said.

The San Diego resident had been backpacking alone for three nights when he was mauled to death by the bear, according to a park service statement.

Photographs found in his camera revealed that White was watching the bear for at least eight minutes near a river before the attack.

"The bear was generally unaware that he was there until the last couple of shots, then his attention turned," park spokeswoman Maureen McLaughlin said.

The photographs "are not that demonstrative" and show "nothing graphic, or any showing major signs of aggression," McLaughlin said. "We're not sure what happened after the camera was put down."

State troopers, park rangers and wildlife biologists, using the photos to identify the "large male bear," shot and killed the animal as it was still "defending the kill site along the Toklat River as the recovery team attempted to reach White's remains," the park service said.

A necropsy of the bear Saturday night confirmed it was the animal that killed White, the statement said.

The first sign of trouble came Friday afternoon, when three hikers noticed an abandoned backpack and signs of a struggle -- including torn clothing and blood -- along the river, the park service said.

The hikers went back to a rest area, about three miles to the south, and alerted authorities around 5:30 p.m. Friday.

About two and a half hours later, park rangers conducting an aerial search spotted at least one grizzly bear and, after touching down, the unidentified victim's remains.

The bear intially ran away, but returned to the site a short time later while the rangers were investigating the scene, forcing the rangers to retreat, the park service said.

After the bear began to circle around them and as darkness was setting in, the rangers decided to wait until Saturday to remove the body.

The area of the Denali backcountry where the attack occurred has been closed -- prohibiting all hiking and camping in that area -- "until further notice," the park service said.

About 12 grizzly bears have been living this summer around where Friday's attack occurred, the park said, citing wildlife biologists.

This attack is the "first known bear mauling fatality" recorded in Denali National Park and Preserve, according to the park service.