Afraid that she might also end up on the wall, she felt trapped. The man hadn’t really hurt her, she said, but he kept her a prisoner and touched her inappropriately. She was afraid he’d never let her go. She was too far from the Strip to walk back even if she could manage to get away from him.

At length, she had seen a chance to run, and she hitched a ride back to the Pacific Highway. She thought that the man who held her captive might be the Green River Killer.

There were hundreds of reports from citizens who were sure they knew who the river killer was,...