Common Pleas Judge Benjamin Lerner is expected to rule on the matter Sept. 16.
The defense attorneys also asked Lerner for an expedited trial date and gave him a list of dozens of potential trial witnesses that included Mayor Nutter, several of his top advisers and the owner of the building that toppled onto a Salvation Army thrift store during demolition on June 5, 2013.
"We believe the mayor has some information regarding this. We believe the mayor was - in some form - part of the investigative team immediately after the catastrophe. As a result, we have subpoenaed and want some of the information the mayor has," Grey said.
Other city officials listed as potential witnesses are: Deputy Mayor for Public Safety Everett Gillison, also the mayor's chief of staff; Mary Stitt, chief of staff for the Managing Director's Office; Deputy Mayor for Economic Development Alan Greenberger; and Licenses & Inspections Commissioner Carlton Williams.
Mark McDonald, Nutter's spokesman, said the mayor had not received formal notice about being a witness and would have no comment.
Also on the witness list is building owner Richard Basciano, who hired general contractor Campbell, 50, to demolish his property near the corner of 22nd and Market streets. Benschop, 43, was hired by Campbell to operate an excavator during the demolition.
Prosecutors contend that the deadly collapse was the result of recklessness, greed and corner cutting by Benschop and Campbell.
The defense attorneys said their clients are scapegoats.
"My position is, the owners, the city of Philadelphia, the architect and the Salvation Army are all responsible for this tragedy," Hobson said.
"My thought is, whoever is responsible hasn't been arrested or charged," Grey said.
Though a grand jury is still investigating the collapse, only Benschop and Campbell have been criminally charged.
Both face six counts of third-degree murder, six counts of involuntary manslaughter and numerous related offenses. They are behind bars without bail. A trial date has not yet been set.
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