Levi Aron, the suspected murderer of an 8-year old Brooklyn boy, was arraigned in New York City court today, after confessing to the killing of Leibby Kletzky, a Hasidic Jewish boy from the Borough Park area of Brooklyn.

NY1 reports that Aron pleaded not guilty Thursday to the first-degree murder and kidnapping of eight-year-old Leiby Kletzky.

Earlier reports said that Aron was charged with second-degree murder.

Aron's defense lawyers expressed concern for the mental health of their client, and requested he be placed on suicide watch.

He has indicated to me that he hears voices and has had some hallucinations, defense attorney Pierre Bazile said.

We have concerns with his mental state. He does appear to be unwell, said another defense attorney. We have to examine him.

It does not seem implausible that Aron's attorneys are setting up an insanity defense, which could signficantly reduce or altogether eliminate jail time even if the court can prove beyond a resonable doubt that Aron killed the boy.

Levi Aron made no attempt to deny his involvement with Leibby's death, pointing police in the direction of the boy's remains when they first apprehended him at his Brooklyn apartment.

Police were led to his Kensington area apartment via a surveillance video that captured Aron conversing with Leibby outside a Borough Park dentist's office.

The office was able to provide enough clerical information that police quickly tracked the suspect down - but it was too late for Leibby.

Levi Aron provided a detailed confession after being taken to police headquaters.  Aron indicated that he did not initially intend to kill the boy, claiming that he panicked after realizing the massive scale of the search effort for him.  But portions of his confession have been questioned for credibility.

NBC New York published excerpts of the confession, which details the hours between the time Levi Aron took the boy and when he killed him, which he said happened the next day.

Daily News reported today that police believe Leibby was more likely killed on Monday, not Tuesday.

In the confession, Aron claims that Leibby initially asked him for a ride to a bookstore, but then had second thoughts.

So I asked if he wanted to go for the ride - (a) wedding in Monsey - since I didn't think I was going to stay for the whole thing since my back was hurting. He said OK, Aron is quoted as saying in the confession transcript.

An NYPD source close to the investigation told an ABC News reporter that police looked into this claim, and that the couple who got married said they did not see the boy there.

The couple reportedly live in Far Rockaway, Brooklyn, but held their wedding in Monsey  - an Orthodox Jewish hamlet in upstate New York, just over the New Jersey border and a little over an hour's drive from Brooklyn.

It is believed that Aron did in fact attend the wedding, but no one has reported seeing the boy with him.

Aron also claimed that he suffocated the boy before dismembering his body, but an intial autopsy was unable to conclusively determine the cause of death. Further tests are pending.

According to the same Daily News report referenced above, there was evidence that the boy was tied with a rope.

Police Commissioner Raymond W. Kelly said Thursday that Aron had cuts and scratches on his wrists and arms, indicating a struggle.

Leibby Kletzky was given permission from his parents for the very first time to walk part of the way home from Boyan Day Camp on 44th Street and 12th Avenue in Borough Park. Leibby and his parents had practiced the route the day before, and had a prearranged meeting point a short distance from the camp.

At some point during the walk, Leibby went off course, and may have asked Levi Aron for directions.

The Borough Park area of Brooklyn has a strong Hasidic Jewish population. Instances of violence and murder within Hasidic communities are extremely rare. 

This is a no-crime area, State Assemblyman Dov Hikind, whose district includes the area, told the Associated Press.

New York City Police Commisioner Ray Kelly described the tragedy as every parent's nightmare.

Obviously in this business you see a lot of violence, but there's usually some sort of irrational twisted logic that's given to why a violent event took place, Kelly said. Here, I mean it's just, it defies all logic and I think that's what's really so, so terribly disturbing about this case. There's absolutely no reason. There's nothing more innocent than an 8-year-old child and to be, you know, killed in this manner it's just ... heartbreaking.