About five years ago, she also took guardianship of one of her adoptive siblings, Izaiah, who was then a teenager. “She decided that he was being abused, so she basically showed up and took him, and essentially said if you want him back, you’re going to have to sue,” her uncle said.

But questions about Ms. Dolezal, if not suspicion that she was not exactly everything she purported to be, were never far away either. In her neighborhood of mostly modest homes south of downtown, one neighbor, Tony Berg, a hydraulics technician who was sitting on his front step with a cigarette on a recent morning across the street from her house, said he saw Ms. Dolezal’s appearance change and at first thought someone else had moved in.

“She was blond — dreadlocks down to here and white skin,” Mr. Berg said, drawing a line across his waist. “Then a year or two later, I began seeing a darker-skinned woman go into the house. She had changed.”

Growing Suspicions

And some of the questions, or doubts, about her racial identity were also being deliberately spread. A columnist at The Spokesman-Review in Spokane, Shawn Vestal, said that he and other people at the paper were approached by a private investigator in early June, more than a week before the first news reports about Ms. Dolezal’s racial identity.

“He did have some of the evidence, or said he did, about what her parents would say about her identity,” said Mr. Vestal, who said he had agreed with the investigator that his name would not be made public.

In the “Today” interview on Tuesday and one that followed on a sister network, MSNBC, Ms. Dolezal, remarkably composed despite harsh criticism aimed at her, stuck to her insistence that racial heredity does not equal identity, and she would not answer questions about whether she had changed her self-identification to merely gain advantage. Mr. Lauer asked if she could have been as successful an activist if she had portrayed herself as white.

“I don’t know,” Ms. Dolezal said. “I guess I haven’t had the opportunity to experience that in those shoes, so I’m not sure.”