A Michigan man who threatened to blow up his van near the White House two days before President Bush's second inauguration stunned a court yesterday by saying he couldn't promise that he wouldn't do it again.

Lowell W. Timmers made the remarks as he was about to be sentenced for making false threats in a Jan. 18 standoff with police that lasted nearly five hours. He has admitted that he parked his van near the White House and pretended that he was going to blow up some gas canisters. It was his way, he said, of protesting his son-in-law's arrest on immigration charges.

The hearing was supposed to be uneventful: Timmers, 54, pleaded guilty in March, and his plea agreement called for a likely 34-month prison term. But when U.S. District Judge Emmet G. Sullivan asked a routine question about whether he had learned his lesson, the proceedings went awry.

"What are the chances of you doing this again?" the judge asked.

Timmers -- dressed in an orange jail jumpsuit, his long, white hair flowing down his back -- paused a moment before speaking up.

"There's always a chance of anything, Your Honor," he said.

The judge's jaw dropped. He pressed Timmers to be clear.

"The odds of that happening are 800 million billion to one," Timmers said, "but I can't ever rule anything out completely, Sir."

Sullivan, who has heard thousands of cases in more than two decades on the bench, said he was "astonished." "I don't think in my entire judicial career anyone's ever told me, 'Yeah, I might do this again.' "

"I didn't mean to upset you," Timmers told the judge at one point.

Defense attorney Tony Axam of the Federal Public Defender's Office tried to explain that Timmers, a self-employed woodcutter, is a "deeply, deeply philosophical person" -- for whom there were no absolutes.

"If you asked him if anything is absolute in this world," Axam said, "he may tell you he's not sure he's standing here."

The judge said that only added to his concerns.

"If he's not sure about whether he's standing here, maybe we need to send him to Butner for a little while for evaluation," the judge said, referring to the federal psychiatric prison facility in North Carolina.

Timmers said nothing in this world is for certain. "I could be dreaming right now," he said.

Sullivan ultimately called a short recess and, after returning to the bench, announced that he would not go forward and complete the sentencing. Instead, he said, he will let the prosecutor and Timmers's defense attorney propose how the court should proceed. He will revisit the issue at a hearing July 20.

The judge acknowledged that other defendants might have lied at their sentencings when asked about their plans.

"Maybe we should reward him for his candor," Sullivan said. "But it's very disturbing. Here's a man, about to go away for 34 months, and he says he might be back."

During the hearing, Timmers showed his candor repeatedly. When Sullivan asked why he accepted the guilty plea, Timmers said he had little choice. "The only other option is a trial," he said. "I obviously am guilty. We have no defense."

Assistant U.S. Attorney Heidi M. Pasichow said she, too, was surprised by Timmers's comments. She said prosecutors had believed that the looming prison term "would provide some deterrence."

Timmers, of Cedar Springs, Mich., drove the van into a secure area near the White House at 15th Street and Pennsylvania Avenue NW. When Secret Service agents tried to get him to move, he flashed his hand, which held what appeared to be a switching device for a possible bomb. Prosecutors quoted him as saying, "I have 10 gallons of gas in here, and I will blow up the van and the White House."

The incident triggered the evacuation of several blocks of downtown and tied up traffic for hours on the first day of inauguration activities. Timmers eventually surrendered peacefully.

"I highly wish I hadn't did it," Timmers said yesterday. "As far as protesting what was going on, I'm glad I did that. I should have done it differently."

Police officers run past Lowell W. Timmers at the wheel of a van stopped on Pennsylvania Avenue NW a block from the White House on Jan. 18.