PHOENIX (AP) _ One of two inmates who held a pair of guards hostage in a prison tower pleaded guilty Wednesday, admitting that he raped a kitchen worker and a female guard during the 15-day standoff.

Steven Coy pleaded guilty to 14 charges _ including escape, kidnapping, assault and sexual assault. Prosecutors did not offer Coy anything in exchange for his plea in Maricopa County Superior Court.

``This is not a plea agreement situation,'' Assistant Maricopa County attorney Jeannette Gallagher said.

Coy, 40, was under heavy guard Wednesday, with seven SWAT team members present and few people allowed in the courtroom. A sentencing hearing was scheduled for April 30.

Coy and inmate Ricky Wassenaar took two guards hostage Jan. 18 in the tower at the Arizona State Prison Complex-Lewis in Buckeye. The male guard was released Jan. 24 and the female guard was set free Feb. 1 _ the same day the inmates surrendered.

Wassenaar has said that the pair initially planned to go to the tower to get weapons and escape but got trapped there. Coy, however, has disputed the claim, declining to explain why they went to the tower.

To end the standoff, Arizona prison officials had agreed to move the inmates to prisons in Wisconsin and Maine. Prosecutors had them moved to Maricopa County to await trial.

Last week, Coy indicated in a media interview that he was frustrated at still being held in Arizona and was considering pleading guilty. Gallagher said Wednesday that she was concerned Coy was trying to manipulate the situation.

``I have concerns that he's not pleading guilty because he is, but because he wants what he wants,'' she told the judge.

However Coy's attorney, Jim Logan, tried to downplay his client's remarks.

``That was a statement made to the press. Take it for what it's worth,'' said Logan, who declined any further comment.