A chemist has pleaded guilty to federal charges that he threatened to kill President Bush, and prosecutors asked a judge to recommend mental treatment.

Details of the threat were filed in a sealed affidavit."It was not a joke on your part?" asked U.S. District Judge John Parker during a hearing Friday.

"No," responded Ashburn, 34, who testified that he has a doctorate in organic chemistry.

But U.S. Attorney Ray Lamonica told Parker that Ashburn did nothing to indicate that he meant to carry out the threat.

The judge freed Ashburn on a $10,000 unsecured bond, and deferred sentencing until Parker receives a background report on him.

Ashburn faces a maximum penalty of five years in prison and a $250,000 fine.