The woman said that she had been traumatized by what happened and that she had been too ashamed to tell anyone, including her parents. But she said she also feared that no one would believe her because Mr. Zimmerman came across as so likable.

“He was always very charming and personable with everyone in the family and would always just laugh and entertain everybody,” she said. “But he was different behind closed doors with me.”

The last encounter, and the only one that took place in Florida, occurred shortly after Mr. Zimmerman arrived in Lake Mary, not far from where she lived with her family, the woman said. She was 16 and Mr. Zimmerman was 18. He had invited her to a housewarming gathering, she said. When she arrived, he was alone. Frightened, she said, she followed his instructions and lay down on a bed, and he started groping her. At that point, she said, she got up, ran out and jumped into her car. He followed her to the door but no farther, she said.

In 2005, when the woman was 19, she confided in her sister, who told their parents, she said. She and her parents went to meet Mr. Zimmerman at a pizzeria in Lake Mary, she said. But she never described to them the full extent of the molesting, she said.

“Instead of talking about it, all he did was come in the room, come in the restaurant, and sat down on the end of the booth and said, ‘I’m sorry,’ and just got up and walked out,” she said.