I authored a review on the first four hearings, you can read the full report here.
For seven years prior to the first hearing, Rep. Peter King had maintained that “80%, 85% of the mosques in this country are controlled by Islamic fundamentalists" and that average Muslims "are loyal," but "don't come forward, they don't tell the police what they know. They won't turn in their own." In December 2010, he staunchly announced that he will “stand-by” the 85 percent number. Today, after eight years, four hearings and eighteen witnesses, King has failed to produce the promised evidence to support his stigmatization of America’s Muslims.
Not a single witness attempted to factually validate the allegation of a Muslim community run by extremists. King made only one foray into backing up his allegation during the entire series of hearings. He asked Zuhdi Jasser if extremism is a “systemic problem” in the American Muslim community. Jasser, a physician who works closely with the anti-Muslim movement, is not an expert and has conducted no research on the topic. Jasser’s response: “It's a minority, but there's an ideology that exists in some mosques-- not all, not a majority -- but in some mosques. And it's a significant number.”
Five of the six law enforcement representatives who testified did not support King’s assertion that Muslims do not cooperate with law enforcement. Instead, these witnesses described “strong relationships” with Somali Muslims, “strong bonds” with the American Muslim community and “outreach and engagement with Muslim communities…” Prior to the hearings, FBI Director Muller had told the House Judiciary Committee, “that many of our cases are a result of the cooperation from the Muslim community in the United States."
Raw Story kindly cited the report in their coverage of this week's fifth hearing:
"An analysis by Council on American-Islamic Relations of King’s first four hearings on Islamic radicalization determined that the chairman had 'failed to produce the promised evidence to support his stigmatization of America’s Muslims.'"
"'King’s record of leveling unsubstantiated allegations and biased attacks on the Muslim community and habit of naming people with records of anti-Muslim bias as potential witnesses and information sources denies him any current credibility in discussions about American Muslims and homeland security,' the group concluded."