An aerial view of various law enforcement vehicles at an intersection at night, with their lights flashing.

F.B.I. and SWAT units raided a home in a neighborhood approximately two miles from Nancy Guthrie’s residence on Friday night.Credit…Brandon Bell/Getty Images

The investigators who swarmed an affluent desert subdivision near Tucson, Ariz., in connection with Nancy Guthrie’s disappearance on Friday night spent hours searching the home next door to David Curl, a retired lawyer who has lived in the neighborhood for 30 years.

Mr. Curl said he and his wife had been unwinding after returning home from a three-week vacation when a sheriff’s deputy knocked on their door with their next-door neighbor, an older woman who Mr. Curl says lives with her adult son.

The woman was home by herself when investigators showed up at about 6 p.m. Friday with a search warrant, Mr. Curl said in an interview on his back patio on Saturday morning. She was not allowed to be inside her home as investigators searched, Mr. Curl said, so the woman instead spent the night at Mr. Curl’s house.

Once the investigators left the neighborhood in the early hours of Saturday, Mr. Curl said he went next door with his neighbor to help her lock up her house. There, he said, he saw a copy of a federal search warrant in the living room. He said the warrant mentioned the Guthrie case.

“She had no idea what they were asking about,” Mr. Curl said of his neighbor. “She had no information about the disappearance or any idea why they were focusing on their house.”

The woman whose house was searched declined to speak on Saturday, and it remains unclear how the search is connected with Ms. Guthrie’s disappearance two weeks ago.

“She’s really distraught,” Mr. Curl said of his neighbor. She told him on Saturday afternoon that her son had been questioned and released and was now with friends.

No arrests have been made in Ms. Guthrie’s disappearance, and investigators said the flurry of activity late Friday into early Saturday at two sites not far from Ms. Guthrie’s home in the Catalina Foothills was related to tracking down leads.

Chris Nanos, the sheriff leading the investigation, has said that law enforcement officials have gotten more than 32,000 leads since Ms. Guthrie, the mother of the “Today” show host Savannah Guthrie, was taken from her home on Feb. 1.