Hearing on radical Islam goes to extremes

>>> now to the congressional hearing today that for a time appeared to blow up in the face of the man who gavelled it into session. new york republican congressman peter king admits he's obsessed with 9/11. he runs the homeland security committee in the house and he has wanted to hold hearings to root out radical islam in the u.s. but things did not go the way he planned. nbc's kelly o'donnell covered today's hearing on capitol hill . kelly , good evening.

>> reporter: good evening, brian. well, congressman king says the reaction is rabid and hysterical. but after the administration said al qaeda is trying to recruit inside the u.s., king says it's his duty to investigate. arriving with the extra security he requested, republican chairman peter king launched a preemptive strike against vocal and angry critics.

>> there is nothing radical or unamerican in holding these hearings.

>> reporter: for weeks king has been accused of discriminating against muslims by focusing only on islamic extremism inside the u.s.

>> it's a back down -- political correctness.

>> i don't see the benefit in stigmatizing, in finger pointing.

>> reporter: democrats who tried to block the hearing even after it began say it played into enemy hands.

>> this hearing focuses on american muslim community will be used by those who seek to inspire a new generation of suicide bombers.

>> reporter: but no one expected what happened next.

>> it's well known that --

>> reporter: tears swept over minnesota democrat keith ellison , the first muslim elected to congress. crying as he spoke of a muslim paramedic killed september 11th .

>> he bravely sacrificed his life to try to help others on 9/11.

>> reporter: ellison said that fallen first responder had been viewed with suspicion because of his faith.

>> his life should not be identified as just a member of an ethnic group or just a member of a religion, but as an american who gave everything for his fellow americans.

>> reporter: a very different personal pain from a national father who testified that his son, charged with killing a soldier in arkansas, had converted to islam and was recruited through a local mosque and then sent to yemen.

>> carlos ended up in a training camp run by terrorists.

>> do the mosques know that they're responsible to the radicalization of your son?

>> sure, they know. but they're waiting around to do it again to someone else's child.

>> reporter: democrats repeatedly protested that this hearing was too narrow and should have included other extremist groups .

>> the klan is a terrorist organization and has been over 100 years, sir. you have not suffered a cross burning .

>> reporter: and democrats rejected king's assertion that some muslims refused to cooperate with law enforcement .

>> muslims are here cooperating. they are doing what this hearing has suggested that they do not do.

>> reporter: and that issue also gets sensitive because there was also evidence presented today that some muslim groups are discouraging muslim americans to come forward. brian.

>> kelly o'donnell after a hot day on capitol hill in washington. kelly , thanks.