ATLANTA, Jan 19 (Reuters Legal) - A U.S. high-school librarian could face criminal charges for conducting online research while she was a juror in a capital-murder trial.

The juror's actions, which prompted the judge in Luzerne County, Pennsylvania, to declare a partial mistrial, appear to be the most serious reported instance of online juror misconduct.

The problem came to light on Friday, when the jury forewoman in the Court of Common Pleas told the judge that Juror No. 11, Gretchen Black, had conducted Internet research about injuries suffered by the victim, and that Black had offered to share her research with the other jurors. By that time, the 12-member jury had already found the defendant not guilty of first-degree murder, but was deadlocked 7 to 5 on charges of involuntary manslaughter and third-degree murder.

Judge Tina Polachek Gartley found Black's actions to be grounds for dismissal from the panel, forcing a retrial of the case on the lesser charges.

Luzerne County Assistant District Attorney Michael Vough told Reuters Legal that he was considering a criminal contempt charge against Black. According to Vough, Judge Gartley had explicitly and repeatedly warned jurors before court recesses not to conduct their own research, including on the Internet. Vough said that Black, a local high school librarian, had already shown she was an especially eager juror. Early in the trial, he said, she raised her hand and asked the judge if she could question a prosecution witness. The judge denied the request.

The facts of the case are particularly grisly. The defendant, Lamont Cherry, stands accused of the May 2009 death of his girlfriend's daughter, one-year-old Zalayia McCloe. The baby died from a fractured skull and brain injuries as a result of severe shaking by Cherry, prosecutors alleged. Black's online research looked at retinal detachment, another injury suffered by the young victim. Prosecutors plan to review trial transcripts and interview the 11 other jurors before deciding whether to file a contempt charge, Vough said.

Judge Gartley assigned a court-appointed attorney, Mark Bufalino, to represent Black in the contempt investigation. Bufalino told Reuters Legal that Black misunderstood the judge's instruction not to conduct outside research, believing she was referring only to facts in the case, not related issues such as how a person could suffer retinal detachment. She just wanted to be the best juror possible, Bufalino said. Black could not be reached for comment. Judge Gartley, reached by phone, declined to comment.

A DILEMMA FOR COURTS

Courts nationwide are struggling with how to prevent jurors from going online during trials. In the last 18 months, at least eight state courts and the federal court system have rewritten civil and criminal jury instructions to bar jurors from tweeting, texting, blogging, emailing, or researching proceedings online. But many jurors are ignoring those instructions. Data compiled by Reuters Legal found that more than 90 trials have been the subject of requests for a mistrial because of Internet-related juror misconduct; more than half of those occurred in the last two years.

Criminal sanctions against jurors are rare. When judges do penalize jurors for Internet misconduct, they almost always opt for fines. In February, a Superior Court judge in Georgia fined a juror $500 for Googling information about a rape case. In May, a Circuit Court judge in Michigan fined a juror $250 and ordered her to write a five-page essay about the constitutional right to a fair trial. (While that trial for resisting arrest was still going on, the juror had posted on her Facebook page: Gonna be fun to tell the defendant they're GUILTY.)

In July, a U.S. District Court judge in South Carolina decided against charging a juror with contempt after he looked up the definitions of exhibit and sponsor on Wikipedia and brought printouts of his findings to the jury room. The judge found that the research was not sufficiently prejudicial to the case, which involved illegal cock-fighting.

Jury experts say that the issue of how to punish jurors who venture online is increasingly posing a dilemma for courts. On the one hand, penalizing jurors for violating prohibitions against Internet use could have a strong deterrent effect. But penalties could also increase resistance to serving on juries. It's a Catch-22 for judges, said Thaddeus Hoffmeister, an assistant professor at the University of Dayton School of Law, who blogs about juries. But as more abuses surface, he said, judges may become more willing to bring the hammer down.

(Editing by Eric Effron and Amy Stevens)