The chairman of the City Council committee that is investigating a confidential audit of Baltimore's speed camera program says the devices should remain offline until he finishes the "thorough" probe.

"We're going to conduct a very thorough investigation," Councilman James Kraft said. "I think the speed cameras should remain off until this is all straightened out."

The council voted last week to investigate the circumstances behind the audit, which was commissioned by the administration of Mayor Stephanie Rawlings-Blake but never released. The study, a copy of which was obtained by The Baltimore Sun, found error rates much higher than officials have acknowledged publicly.

URS Corp., the national engineering firm that performed the audit, found that the camera system run by Xerox State and Local Solutions in 2012 had an error rate of greater than 10 percent, The Sun reported last month.

City lawyers have refused repeated requests to release the audit, citing "attorney work product privilege." Mayor Stephanie Rawlings-Blake, responding to The Sun's reporting, said last week that URS was "not sufficiently qualified" to do a thorough report. She called the 90-page audit "incomplete."

Council members have said they want to know who in the Rawlings-Blake administration knew about the audit's findings and when they knew it. Members said they would demand all documents prepared by URS on the city's speed and red-light camera program.

A spokesman for Rawlings-Blake said the mayor welcomes the probe and does not plan to rush the speed cameras back into operation.

"There are no immediate plans to bring the speed camera program back online and we do not anticipate doing so while the council conducts its investigation," spokesman Kevin Harris said in an email. "The Mayor looks forward to working with the council and continuing our efforts to bring all the facts to light and correcting a lot of misinformation being spread about the speed camera program."

Harris objected to "rhetoric being thrown around alleging a cover up and [that] does not put the URS report in its proper context so that citizens can see the whole truth and not just what people want to seize on to promote a political agenda."

Kraft said Tuesday he is asking for the authority to refer individuals to law enforcement if they are suspected of wrongdoing.

"This is a serious matter," Kraft said.

Kraft spoke after his Judiciary Committee assumed control of the investigation, rebuffing an attempt by City Councilman Carl Stokes, chairman of the Taxation and Finance Committee, to lead the probe.

Stokes, who was the first council member to call for the investigation, asked whether other members of the council were independent enough from the administration to conduct the probe.

"I was disappointed," Stokes said. "For no good reason, frankly, it was hijacked away from the Taxation and Finance Committee." He said he was concerned about the possibility of a "whitewash" if his committee did not lead the investigation.

"Today could have been the first day of the investigation itself," Stokes said. "Yes, I'm angry. Yes, I'm upset, because the people in the streets are upset. They're mad. They're angry. We ought to respond to that, not try to cover each other's behinds in this building. That's not why we're sent here. We're not sent here to cover each other's behinds."

Kraft said his committee would take the matter seriously.

"I'd like to know what the councilman is talking about," he said, referring to Stokes. "What is your evidence of corruption? If you have evidence of corruption, then produce it. If you don't have it, then you need to stop saying it. Very frankly, put up or shut up."

In 2012, when The Sun was reporting on problems with the speed cameras, officials from the mayor's office and the city Transportation Department said repeatedly that the system as run by Xerox had a very low error rate.

Khalil Zaied, then the head of the city's Transportation Department, wrote in a letter to The Baltimore Sun that the rate was "less than a quarter of one percent." Zaied was later promoted to deputy mayor.

Xerox operated Baltimore's speed camera program from the fall of 2009 through 2012, when the city put the contract out for bid again. After The Sun found erroneous speed readings at seven cameras, Xerox said it had detected an error rate of 5.2 percent at five cameras and took them off line in the weeks before its contract ended.