Schulle took aim at District Attorney Seth Williams, noting that Williams is not bound by the recommendations in the 110-page grand jury report released Monday.
"The district attorney seems more interested in maintaining a high conviction rate than taking on difficult cases," Schulle said.
Williams rebutted that assertion Tuesday, pointing to his office's prosecution of members of "the Catholic Church hierarchy" for crimes related to the priest sex-abuse scandal.
"We are not afraid to prosecute anyone for any offense, and we have done that repeatedly," he said.
The biggest challenge to prosecuting the New York-based building owners, Nahman and Michael Lichtenstein, was the fact that the cause of the fire was never determined, Williams said.
Williams and the grand jury were highly critical of the Lichtensteins for not responding to the city's notices of code violations before the fire, and for not securing the property against drug addicts, scrap-metal scavengers, and squatters.
While one of those intruders likely started the fire, "that's not enough in a court of law," said Ed McCann, Williams' first assistant district attorney.
"I can't stand in front of a judge and say the fire was caused because the owners didn't secure the property. That's a threshold issue," he said Tuesday. "If we can't do that, we don't have a prosecution."
McCann compared the fire to the Pier 34 nightclub collapse into the Delaware River in 2000, killing three women. After a legal battle that went all the way to the state Supreme Court, the club operator pleaded guilty to two misdemeanors and the owner pleaded no contest. Both received house arrest.
In that case, McCann said, prosecutors had evidence that both men had been warned that the pier was in imminent danger of collapse. There was no similar link with the Lichtensteins, he said.
"If we had evidence that the fire was started by someone who broke into the property . . . then we might be in a different situation right now," he said.
Schulle, however, drew a different comparison - to the 2004 fire that killed Capt. John Taylor and Firefighter Rey Rubio. That blaze started when a basement pot farm smoldered into flames. The home's owner was convicted of involuntary manslaughter.
"The circumstances were different, but in both situations, the owners were negligent," Schulle said. "We understand that it's a difficult case, but it's a fight worth fighting."