A 13-year-old girl pleaded guilty to mailing threatening letters to President Clinton, his family and other officials, while a second girl denied taking part and demanded a trial.

The guilty plea came at a pretrial hearing Friday in Wayne County Juvenile Court. Judge Patricia Campbell ordered a psychological examination for the girl by July 24.

Under Michigan law, she could be warned, placed on probation or held until her 19th birthday. A June 27 trial was set for the second girl, also 13 years old.

Both girls, who were arrested in April, remain free but with electronic tethers to monitor their whereabouts.