The lawyer for Griffin Campbell, the demolition contractor found guilty in the deadly 2013 Center City building collapse, filed an emergency motion Thursday asking that the verdict be overturned because of "selective racial prosecution."

At issue, defense lawyer William D. Hobson contends, is that the Philadelphia grand jury probe that led to charges against Campbell and excavator operator Sean Benschop was supervised by Assistant District Attorney Frank Fina.

Fina is the former state prosecutor accused by Pennsylvania Attorney General Kathleen G. Kane of using government computers to swap pornography and racial and ethnic jokes among a group of fellow state prosecutors and state officials, including Supreme Court Justice J. Michael Eakin.

Although the dispute between Kane and Fina is much broader than the emails, the fact that some emails involved crude racial humor gave Hobson new ammunition in his long-standing contention that racial bias tainted the probe into the June 5, 2013, collapse that killed six and injured 13.

Hobson's motion asks Common Pleas Court Judge Glenn B. Bronson to postpone Campbell's sentencing, now scheduled for Jan. 8, so the judge can conduct his own probe of the fairness of the process that led to the criminal charges.

Bronson set a hearing on the motion for Friday.

The District Attorney's Office denied the allegations made in the motion.

"All prosecution decisions in this case were based solely on the evidence and nothing else," said Kathleen Martin, the district attorney's general counsel and chief integrity officer. "Race was not involved in this matter, nor is it ever in any case. All final decisions on charging are made by the district attorney himself, and none of the charging decisions here were made by Frank Fina."

At Campbell's trial, prosecutors objected to Hobson's bringing up the issue of selective prosecution based on race.

Fina and two other prosecutors involved in the email exchanges when they worked for the state Attorney General's Office subsequently joined the staff of Philadelphia District Attorney Seth Williams.

Public pressure has continued to build from women's groups and City Council demanding that Williams fire Fina and prosecutors E. Marc Costanzo and Patrick Blessington.

Williams has resisted. He had the three undergo sensitivity training last month and then reassigned them to jobs where they have no direct role in building or prosecuting criminal cases.

Throughout the collapse trial, Hobson tried to cast the case as one in which the white establishment was making a scapegoat out of working-class African Americans from North Philadelphia.

After a two-year grand jury probe of the collapse at 22d and Market Streets, only two people were criminally charged, both African American men: Campbell, 51, and Benschop, 44.

Benschop, whom Campbell hired, was operating an excavator to raze a building adjacent to the Salvation Army store when an unsupported three-story brick wall toppled and crushed the single-story store. Benschop pleaded guilty to six counts of involuntary manslaughter, 13 counts of reckless endangerment, and one count of aggravated assault.

The architect overseeing the demolition, Plato A. Marinakos Jr., 49, who is white, was granted immunity from prosecution. He testified before the grand jury and at the trial where Campbell was found guilty of six counts of involuntary manslaughter, 13 counts of reckless endangerment, and single counts of aggravated assault and causing a catastrophe.

Other principals, such as multimillionaire property developer Richard Basciano and his top aides - all white - were allowed to invoke their Fifth Amendment right against self-incrimination, and declined to testify before the grand jury.

The motion filed Thursday argues that Fina's emails "cast grave doubts upon his ability to be fair and impartial, race neutral, and sensitive to the needs of the African American community of Philadelphia while serving in his prior role as the lead sole supervisory district attorney for the Market Street collapse."

Hobson is not the first to use Fina and the email controversy to try to undermine a criminal case. Last week, a Dauphin County judge ordered Fina to testify about what role, if any, race played in the investigation that led to corruption charges against State Rep. Louise Williams Bishop, a West Philadelphia Democrat.

Bishop is among six current or former Democratic elected officials from Philadelphia charged by the District Attorney's Office with taking money from a lobbyist-turned-informant who sought political and legislative favors. All six are black. Four have pleaded guilty.

That investigation originated in the state Attorney General's Office and was supervised by Fina. After Kane took office in 2013, she shut down the case, contending the sting targeted only black officials.

Fina subsequently left for the Philadelphia District Attorney's Office, where Williams, who is black, resurrected the probe and brought charges against the six. Bishop's lawyer, A. Charles Peruto Jr., is challenging the charges against her, contending the sting may have targeted black elected officials solely because of race.

215-854-2985 @joeslobo