Much of the evidence that prosecutors used to convict R. Kelly came from the singer himself.
He obsessively collected message slips and letters written by the women he interacted with — some of them underage — according to Ryan Chabot, the lead federal investigator in the case. Mr. Chabot said he sifted through the evidence recovered from several searches of the singer’s Chicago apartment and storage facility.
Mr. Kelly kept some of the evidence in FedEx folders, with labels like “Old Messages,” and other pieces — like a seven-page, front-and-back, handwritten letter from a woman who testified for three days early in the trial — in protective sleeves in a locked safe.
Calling Mr. Kelly a “great man,” the woman wrote: “At the age of 17 I never had sex with Robert Kelly,” then proceeded to tick off a list of specific sex acts that she said she had not participated in with the R&B superstar.
Less than two years later, when the woman who had written the letter testified under a pseudonym, she said she had experienced coerced and recorded sexual encounters with the singer starting when she was 17. He hit her often, she said, and forced her to get an abortion.
Every letter that prosecutors introduced at trial came from Mr. Kelly’s personal collection in what appeared to be a yearslong attempt to build his defense even before the indictment in Brooklyn was unsealed. They were all signed by accusers who were at the forefront of the case against the singer.
Those accusers now say he forced them to write the letters, including a man who testified that the singer told him what to write “word for word.”
The material, known as “collateral,” makes it difficult for victims to escape, said Dawn M. Hughes, a clinical and forensic psychologist who provided expert testimony for the prosecution. (She also testified as an expert at the trial of Keith Raniere, the Nxivm cult leader, who also relied on such collateral to intimidate women he was abusing.)
Creating collateral keeps adolescents “captive,” she said, and creates a power dynamic she likened to “slowly sucking the oxygen out of the room and once you realize it, you can’t get out.”