Assistant District Attorney Edward Cameron said Knellinger, 42, is the only person who has been charged in the April 9, 2012, fire that destroyed the vacant Thomas W. Buck Hosiery complex on York Street off Kensington Avenue.
The blaze in the city-block complex killed Lt. Robert Neary and Firefighter Daniel Sweeney and injured two others when one of the mill's five-story brick walls toppled onto Knellinger's furniture store, Giamari Furniture & Bedding on Kensington Avenue.
Knellinger's criminal case involved lies he told a grand jury that spent two years investigating the fatal blaze.
Cameron said Knellinger testified before the grand jury and denied speaking with Nahman and Michael Lichtenstein, the Brooklyn, N.Y.-based father-and-son speculators who bought the property in 2008, and a man they hired to live there to secure the vacant mill. Knellinger also lied when he told the grand jury he was not present at the fire scene.
Authorities said drug addicts, scrap-metal scavengers, squatters, or other intruders likely caused the fire that destroyed the old mill, although a cause was never determined.
Without an official cause, or a link showing the Lichtensteins were aware of the hazards caused by the unsecured mill, the grand jury could not recommend criminal charges against them, according to prosecutors.
Since the fire, more that 30 civil lawsuits have been filed in Common Pleas Court against York Street Property Development, the business entity the Lichtensteins created to buy the property and convert it into apartments.
The civil lawsuits are pending, including wrongful death cases filed by the families of the dead firefighters.