Kenneth Barnes says one thing in particular bothers him about the bank robbery plot he's serving 45 years in federal prison for, in which authorities say he and a woman forced a pizza deliveryman to wear a bomb locked to his neck.

Testifying against the woman, Barnes said Thursday that the deliveryman became skittish once he realized the metal device about to be collared on him contained a real bomb, so Barnes punched him in the face.

"I'm not proud of that," Barnes said, pausing for emphasis during his rapid-fire testimony in the trial of Marjorie Diehl-Armstrong of Erie on charges including armed bank robbery.

Diehl-Armstrong has said she was framed for the plot that killed 46-year-old pizza delivery driver Brian Wells on Aug. 28, 2003, when the bomb he was wearing exploded as he sat handcuffed in a parking lot after state police arrested him as he left the bank.

Barnes' testimony so angered Diehl-Armstrong, 61, that she became unruly and made several unintelligible comments, prompting U.S. District Judge Sean McLaughlin to dismiss the jury. While they were away, the judge read a rule allowing him to remove a defendant that persists in unruly behavior.

After reading it, McLaughlin told Diehl-Armstrong, "You are now on notice."

Barnes testified that Diehl-Armstrong asked him to join the plot that summer and told in detail of things he saw her say and do to advance it.

Barnes, 56, ran a "crack house" but wasn't successful because, he said, he smoked too much of the drug himself. He met Wells through a prostitute, who serviced Wells in an upstairs bedroom at Barnes' house. That woman, Jessica Hoopsick, testified briefly Thursday, setting the stage for Barnes' testimony.

Barnes said Diehl-Armstrong wanted to rob the bank so she could pay Barnes to kill her father, now 91-year-old Harold Diehl, who has not been in court. Barnes said Diehl-Armstrong was upset because her father was spending money she thought she'd inherit and was donating too much of it to a church.

Barnes said he lied and told her he had killed someone for hire in the past.

"I jokingly said I charged him $250,000," Barnes said.

But Barnes said Diehl-Armstrong was deadly serious and even explained how she wanted it done, telling Barnes to hit her father over the head, then throw him down cellar steps to make it look like an accident.

Barnes himself was serious about the robbery plot, however, saying he wanted his share of the loot.

"I was gonna go up to Buffalo, buy a lot of crack and come back and be a millionaire," Barnes said. "But that didn't work out because I smoked up my own product."

The day before the robbery, Barnes said, he met with Diehl-Armstrong, Wells and another conspirator, handyman William Rothstein, who has since died of cancer. At that meeting, Barnes said, Diehl-Armstrong measured Wells' neck as he tried on the bomb collar.

Federal prosecutors have said they believe Wells may not have realized until it was too late that he was to be wearing a live bomb. Barnes' testimony about another meeting just before the robbery supported that assertion.

Rothstein called from a pay phone to order two pizzas that Wells delivered to a TV tower next to Rothstein's home. Prosecutors believe the call was a ruse to provide cover for Wells meeting the others, where he would put on the collar bomb.

Barnes said the original plan had been for the device to be "a gag that was supposed to get the teller to give him some money."

But Barnes said Wells sensed something amiss: "I think at that point he realized this thing was real," he said.

Wells turned to run, prompting Rothstein to fire a warning shot into the air while two hangers-on who knew Rothstein tackled Wells, who was forced to wear the collar and given handwritten instructions about robbing the bank and a series of stops he had to make to defuse the bomb later. Prosecutors have said they believe those instructions were intended not to help Wells but to confuse police if the plot were discovered.

That's also when Barnes punched Wells, to get him to submit.

After the judge's warning, Diehl-Armstrong mostly kept her peace. She turned to friends during one recess to deny the charges again, saying, "I'm the only one who doesn't need to rob a bank out of this group."