According to court filings, the juror knew the medical examiner and sent her a message congratulating her on doing a "great job" during her testimony.
The Tennessee Supreme Court ruled on Tuesday that the judge in William Darelle Smith's 2010 murder trial should have conducted a hearing on the Facebook communication as soon as he learned of it.
The Supreme Court said the communication may have been harmless, but it is impossible to know because no hearing was conducted. The trial court was ordered to conduct a full hearing. If it cannot do that, Smith is to be granted a new trial.