Washington (CNN) Michael Cohen, President Donald Trump's former personal attorney, watched former special counsel Robert Mueller's highly anticipated testimony Wednesday in a packed common room of inmates a federal prison in New York.

In a statement provided to CNN, Cohen -- writing from Federal Correctional Institution Otisville in Orange County, New York -- expressed disappointment with Mueller's "reluctance" to extrapolate beyond the report he released in April.

"Mr. Mueller today had the world stage to answer questions regarding obstruction of justice and witness tampering. Sadly, his reluctance just continues to leave the debate open and those responsible free from prosecution ... for the moment," he said. "The American people deserve more!"

In his testimony Wednesday before the House Judiciary and Intelligence committees, Mueller offered mostly terse responses to pointed questions from lawmakers in an attempt to let his report guide his testimony.

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