Levi Aron, the man accused of killing and dismembering a Brooklyn boy on July 11, pleaded not guilty at his arraignment Thursday morning.

The 35-year-old appeared in Brooklyn's State Supreme Court, and was charged with kidnapping and murdering eight-year-old Leiby Kletzky. The boy had gotten lost in Borough Park and asked Aron for directions, according to prosecutors.

Aron, after undergoing a psychiatric evaluation, has been found fit to stand trial and proceed -- even though he has talked about hearing voices.

"Fitness to proceed only includes that he understands the nature and charges against him, that is he able to understand he's being criminally prosecuted, he knows what those charges are, and is able to participate in his own defense. It is not a rendering on sanity or insanity, it is only on competency," said Defense Attorney Jennifer McCann in The Wall Street Journal.

Brooklyn District Attorney Charles Hynes said in a statement "Now that Mr. Aron has been found fit to proceed, we will move forward expeditiously to bring his case to trial. I want to reaffirm that this case will go to trial and that there are absolutely no circumstances which would lead me to accept a plea bargain."