Palm Beach Circuit Judge Jeffrey Colbath is to question juror Dennis DeMartin, 68, of Delray Beach, Fla., on Friday, the South Florida Sun-Sentinel reported Tuesday.
The Sun-Sentinel reported Thursday DeMartin said in a 33-page self-published book he drank three vodka tonics as part of an experiment to determine what Goodman's condition would have been if he had consumed three drinks the night of a February 2010 accident in which Scott Wilson, 23, was killed in Wellington, Fla.
Goodman, 40, was convicted in March of DUI manslaughter and vehicular manslaughter and faces up to 30 years in prison.
But the Sun-Sentinel said the judge's decision to interview DeMartin makes it uncertain whether the sentencing will proceed.
Colbath could decide to overturn the conviction, the newspaper said.
Jurors are forbidden from conducting their own research or investigations in a case and must base their verdicts only on evidence presented in court.
Colbath had told jurors of the rule twice during the trial.
DeMartin wrote the three drinks had put him in a "confused" state and helped him conclude Goodman wasn't fit to drive.
Goodman's defense called DeMartin's experiment an "egregious" example of juror misconduct and asked the judge to overturn the conviction.