On July 22, POLITICO began receiving emails from an anonymous account. Over the course of the past few weeks, the person — who used an AOL email account and identified themselves only as “Robert” — relayed what appeared to be internal communications from a senior Trump campaign official. A research dossier the campaign had apparently done on Trump’s running mate, Ohio Sen. JD Vance, which was dated Feb. 23, was included in the documents. The documents are authentic, according to two people familiar with them and granted anonymity to describe internal communications. One of the people described the dossier as a preliminary version of Vance’s vetting file.

The research dossier was a 271-page document based on publicly available information about Vance’s past record and statements, with some — such as his past criticisms of Trump — identified in the document as “POTENTIAL VULNERABILITIES.” The person also sent part of a research document about Florida Sen. Marco Rubio, who was also a finalist for the vice presidential nomination.

The person said they had a “variety of documents from [Trump’s] legal and court documents to internal campaign discussions.”