Kidnapped by a Fireman

This book is about a young girl living in Atlanta in the late 'eighties trusting a fireman whom she and all the kids called Uncle--who worked next to Atlanta Zoo, at the fire station. She was brutally raped and beaten by two men with a gun pointed at her head--not realizing this fireman she had known all these years looked just like the Atlanta's missing-and-murder children killer. They could go for twins.