BIG BEAR LAKE, Calif. (AP) — Clear skies allowed aircraft with heat-sensing technology to aid scores of officers searching in the snow-covered San Bernardino Mountains for Christopher Dorner, the former Los Angeles police officer suspected of killing three people in a vengeance-fueled rampage aimed at those he blames for ending his career.

Two sheriff’s choppers flew low over the forest Saturday as SWAT teams fanned out to look for tracks in the fresh foot of powder that fell overnight.

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It’s the third full day of the massive multi-agency effort to hunt Dorner down. He’s continued to elude authorities whose last clue of his whereabouts was a burned-out pickup truck found Thursday in this ski resort town.

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Investigators continue to analyze the truck to try and determine whether Dorner torched it or if it caught fire for other reasons.

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(Copyright 2013 The Associated Press.)