About a year after he moved into her house in Queens, their relationship soured. One day, he cornered her, taped her mouth and raped her, she said. Mr. Ramrattan was arrested.

But he soon took his revenge, the authorities said. Drawing on his knowledge of police procedure, gleaned from his time as an informer for law enforcement, he accomplished what prosecutors in New York called one of the most elaborate framing plots that they had ever seen…

“Few people have the capacity to pull off a master plot of this magnitude to exact revenge,” Mr. Brown said.

Mr. Ramrattan framed Ms. Sumasar because she would not drop the rape charge, prosecutors said.