As we report in Sources Say this week: "On June 25, the police disciplinary office began to investigate the weekend melee. Does this investigation mean police can't comment on the case anymore? 'Hahahah!!' SPD spokeswoman Renee Witt wrote in an e-mail. 'That is exactly what it means.'"

Investigations into officer misconduct by the SPD's Office of Professional Accountability (OPA) are widely (and rightly) viewed as a bureaucratic mechanism to exonerate officers of wrongdoing. When cops are found guilty, they are disciplined with the wettest of noodles (usually a few days off work). And even then, a byzantine system for assigning verdicts makes it nearly impossible to discern if a complaint was sustained, the US Department of Justice found last December.

So OPA investigations are not being used to discipline, exactly. Once the department begins an investigation, officers are using OPA investigations as a shield from scrutiny and as an excuse to dodge questions.

And then they're laughing about it.

In this particular case—when officers pepper sprayed people point-blank in the face—nobody had filed a complaint with the OPA to begin the investigation; the police department triggered it internally, sources at City Hall tell me, thereby granting cops carte blanche to stay silent on the case and withhold records.

We've received many more witness accounts from last Saturday's pepper-spray bonanza. But the Mayor Mike McGinn's office has repeatedly failed to answer questions about whether pepper-spray was used as "a self-defense tool, or as a last resort option when all other legal, effective force options have been exhausted," as per the mayor's 20/20 police reform plan. And when you ask the cops, they think it's funny that they can hide behind a pro-forma investigation. If it's an excuse for cops to remain silent, then it's the mayor's job to speak up.

But McGinn is MIA.