PITTSBURGH — A pizza deliveryman who robbed a bank while wearing a collar bomb that later exploded had his neck measured for the device, and earlier took part in talks about wearing a fake explosive, according to documents unsealed Wednesday.

The information was part of an application and affidavit for a search warrant. It also alleges Marjorie Diehl-Armstrong, 58, charged last week in connection with the Aug. 28, 2003, robbery of a PNC Bank in Summit Township, Erie County, told a witness in prison that the late William Rothstein, an unindicted coconspirator in the case, helped make the bomb that killed 46-year-old pizza deliveryman Brian Wells.

"Diehl-Armstrong also told (the witness) that Rothstein and Wells knew each other and stated 'they even measured Wells' neck for the device'," the affidavit states. "Diehl-Armstrong further stated Wells had knowledge of the plan, but did not know the extent of his participation."

Wells told police he had been forced at gunpoint to wear a time bomb around his neck and rob the bank. The device exploded while police waited for the bomb squad to arrive, killing Wells.

Prosecutors named Wells as an unindicted coconspirator, although U.S. Attorney Mary Beth Buchanan has said his role might have "transitioned from that of the planning stages to being an unwilling participant in the scheme."

Wells' family insists he had nothing to do with the plot and did not know the suspects.

The warrant was for the home of Kenneth E. Barnes, also charged last week with robbery, conspiracy and a firearms violation in connection with the PNC heist. Barnes, 53, who is jailed in Erie County on unrelated drug charges, and Diehl-Armstrong have pleaded not guilty.

Diehl-Armstrong was linked to the Wells case after the body of her boyfriend, James Roden, was found in a freezer in Rothstein's home near where Wells made his final delivery. Diehl-Armstrong is serving seven to 20 years in a state prison after pleading guilty but mentally ill to killing Roden in 2003. Rothstein died of cancer in 2004.