The F.B.I. can follow several leads. They can interview Mark Judge, Leland Keyser and P.J. Smyth, high school friends of either Dr. Blasey or Judge Kavanaugh. Dr. Blasey has said they were at the party. Mr. Judge said on Friday that he would be willing to talk to law enforcement officials.

Agents could also investigate several details that could corroborate Dr. Blasey’s story. Weeks after she was assaulted, Dr. Blasey said, she saw Mr. Judge at a local Safeway grocery store. In his book, “Wasted,” Mr. Judge wrote that he worked as a bag boy in a local supermarket. The F.B.I. could ask either Safeway or Mr. Judge for employment records to determine whether he worked there during that period.

If they find any records, they could bolster Dr. Blasey’s credibility and potentially narrow the window of time in which the assault could have happened.

Agents could also study Judge Kavanaugh’s calendars from the summer of 1982 for possible dates and locations for a party like the one Dr. Blasey described and ask Columbia Country Club — where Dr. Blasey said she swam earlier that day — for visitor logs or other records dating to that summer.