"Some things aren't adding up," said Unified Police Lt. Justin Hoyal.
About 50 officers and 20 firefighters converged on the area around the girl's home near 13900 South and Friendship Drive (5755 West) to find her.
On Wednesday morning, Unified Police officers were going door-to-door looking for the girl. They looked everywhere she would or could go, and called on a Utah Highway Patrol helicopter to expand the search. Officers with all-terrain vehicles and search dogs also have been scouring a popular walking trail near her house.
By afternoon, the city emergency operations called for Community Emergency Response Teams and volunteers to join the search. The local Church of Jesus Christ of Latter-day Saints stake also asked for volunteers to find the girl through a phone tree.
Hoyal said that close to 100 volunteers showed up to help in the search, but any volunteers who show up after dark will be turned away. Hoyal added that volunteers may be needed again on Thursday morning.
Officers will keep searching into the night, when temperatures are expected to drop to 33 degrees, with winds up 20 mph, which will make the nighttime air feel more like 17 degrees.
"We'll keep looking until we find her," Hoyal said.
Investigators did not find any signs of forced entry or abduction, though police are not ruling out that possibility, he said.
Anyone with information of Gittins' whereabouts is encouraged to call the Unified Police Department at 801-743-7280.