The FBI announced Thursday it has increased the reward for information leading to Nancy Guthrie and/or the arrest and conviction of anyone involved in her disappearance to $100,000.

The reward was previously $50,000.

Since Feb. 1, the FBI said it has received more than 13,000 tips in the case.

The Pima County Sheriff’s Department said "several items of evidence" have been recovered, including gloves. The evidence is being analyzed, authorities said.

The sheriff’s department also said it is using Ring's Neighbors app to reach out to residents in the area. The department said it’s requesting any video footage from Jan. 1 to Feb. 2 "that includes vehicles, vehicle traffic, people/pedestrians, and anything neighbors deem out of the ordinary or important to our investigation."

The FBI and the Pima County Sheriff’s Department are looking into a video posted online that shows a man in a backpack about 5 miles from Nancy Guthrie’s house shortly before her abduction, sources told ABC News.

The backpack on the video may be different from the backpack in the doorbell camera footage from Nancy Guthrie’s house, sources said.

-ABC News' Aaron Katersky and Trevor Ault

Investigators arrived at Nancy Guthrie’s home on Thursday morning to briefly erect a white tent -- typically used for privacy -- outside her front door.

Investigators took the tent down after about an hour and drove away in unmarked vehicles with a large pelican case labeled "video forensics." They also carried what appeared to be a laser measuring device.

-ABC News' Aaron Katersky