Top brass within the Frateral Order of Police have lashed out at District Attorney Seth Williams for deciding not to press charges against Buffalo Bills running back LeSean McCoy after an ugly bar fight involving two off-duty police officers in February. 

Williams said Monday that a combination of a lack of evidence and conflicting reports the night of the fight at Recess Lounge in Old City did not meet the legal threshold to press charges.

The news spurred a backlash from the Fraternal Order of Police Lodge #5, whose president vowed to appeal to the state attorney general’s office for further review.

“It seems legal for somebody to commit assault in a bar all of sudden now in the city of Philadelphia,” said John McGrody, vice president of FOP Lodge #5.

RELATED: LeSean McCoy will not face charges for Philadelphia bar fight

“Trust me, we have spoken to our members, the investigators, and we know what occurred here and everybody involved in this case here believes that criminal charges are warranted. These are veteran cops that conducted these investigations. I think [Williams] has opened up a can of worms for defense attorneys now in this city.”

McCoy and former running back Curtis Brinkley were accused in February of taking part in the fight over a bottle of champagne that left two off-duty police officers hospitalized.

During a crowded press conference Monday, Williams laid out his case for declining to bring charges.

He said that looking back at the events that look place on Feb. 7 between all parties involved, there was insufficient evidence to prove – beyond a reasonable doubt – who started the fight and under what circumstances.

“I do not condone bar fights,” Williams said.

“But my job is not to decide if anyone acted appropriately or not. My job is to determine if evidence exists to charge any individual with a crime. I do that by looking at all the facts. That is what we did here. My decision is consistent with my commitment to the citizens of Philadelphia to charge, and only charge, those people who, based on evidence, are guilty of crimes.”

Williams said that findings in his investigation resulted in material of the following – that only two interviewed individuals gave any information about how the physical contact initiated and both versions directly conflicted with one another; both participants in the fight declined to file police reports immediately following the incident; each injured participant declined medical attention immediately following the incident; and multiple participants misidentified those involved when speaking to police.

“I don’t make decisions based on politics,” said Williams.

“We didn’t make this decision based on who’s going to be happy or who’s going to be upset or who a potential victim or potential defendant was. That would be wrong for us.

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“In this case, we had evidence that would conclude that people were being justified in trying to protect their friends, and so for all of those reasons, I’m very satisfied that we did the right thing.”

McGrody pledged to take the case to federal authorities, if need be.

“We don’t believe the decision was made based on the facts. We don’t believe the decision was made based on the evidence, and we’re going to do what we have to do to assure these individuals are held accountable, criminally, for what they did," he said.

"We’re going to reach out to the attorney general’s office in Pennsylvania and federal authorities if the local prosecutor is not going to charge somebody with aggravated assault.”