Murder suspect Levi Aron is escorted out of a New York Police Department precinct in Brooklyn
Murder suspect Levi Aron is escorted out of a New York Police Department precinct in Brooklyn, New York, July 14, 2011. Aron is under arrest in connection to the dismembered remains of Leiby Kletzky, 8, who had gotten lost walking home from camp, found in a freezer and a trash container on Wednesday. Reuters

Thursday, Levi Aron pleaded not guilty to charges of the first-degree murder and kidnapping of Leiby Kletzky, a Brooklyn boy whose dismembered body parts were found in a freezer and a dumpster.

The 35-year-old accused murderer claimed that he hears voices and suffers hallucinations, and will undergo psychiatric evaluation.

I have some serious concerns about the client's mental state, his cognitive ability. He's indicated to me that he hears voices and there's some hallucinations involved, as well, said Pierre Bazile, one of Aron's defense attorneys, reports NY1.

In 2006, Aron's ex-wife Deborah Kivel had claimed Aron was a physically abusive psycho, who needed medicine to handle a behavior disorder, said New York Post.

According to a protective order filed in Memphis back then, Aron has been diagnosed with a behavior disorder and takes medication for the condition.

Before Kivel divorced Aron, the accused child butcher worked as an actual butcher at a kosher deli in a Kroger supermarket in Germantown, Tenn, reads the NY Post report.

Aron's marriage ended violently, when he hit her from envying Kivel's more intimate relationship with her children than him.

The past isn't merely past, at least it seems in this case. Kivel was shocked by the murder, saying I had spoken to him not long ago, and everything seemed to be just fine.

Aron will undergo a 730 examination, where two independent medical professionals will examine the defendant to consider the medical evidence. The examination is governed by Section 730 of New York Criminal Procedure Law, and is ordered by court when a defendant's capacity to understand the proceedings and participate in his defense is in question.

At his arraignment Thursday afternoon, Aron appeared disheveled, confused and pale, reports the Associated Press. He remained silent during the brief court proceeding. He was held without bail, placed on suicide watch and protective custody after his lawyers said they feared he could do harm to himself, said the AP report.

A grand jury is currently reviewing the evidence against Aron, said Brooklyn District Attorney Charles Hynes.

Right now the jury is hearing the testimony. I expect that the testimony should be concluded by tomorrow, and then we will ask for the main charge of felony murder, based on the kidnapping, which is murder in the first degree, and whatever other charges we think are sustainable, Hynes said.

According to NY1, Police Commissioner Ray Kelly announced Thursday that the medical examiner believes Leiby may have been smothered or suffocated. The exact cause of death will be determined by further lab tests.

Scratch marks on the man's arms indicate the boy put up a fierce struggle, Police Commissioner Ray Kelly commented on Thursday.

Aron's neighbors said that Aron was never considered part of the community, which pulled together in times of crisis, says Reuters. We're a very closely knit community where everyone knows everyone. He's more of an outcast or an outsider, said David Green, who lives nearby.

The worst nightmare possible

8-year-old Leiby Kletzky went missing on Monday afternoon, as he walked home alone for the first time from day camp. The boy got lost and then approached Levi Aron, who had just made a payment to a dental office nearby, to ask for directions to meet his parents at an agreed location.

Aron convinced the boy to get in his 1990 Honda Accord amd took the boy to his attic apartment. According to Aron's confession, it was the massive search for the boy that caused him to panic, and eventually kill the boy.

When police raided Aron's Brooklyn apartment on Wednesday, the boy's feet were found in Aron's refrigerator, and the rest of the body parts were found wrapped in a black plastic garbage bag, inside a red suitcase that had been tossed into a nearby dumpster.

Kletzky's funeral on Thursday drew thousands of people. Three rabbis spoke at the funeral service. The boy's father also spoke briefly, thanking God for such a beautiful child with a beautiful soul, reported CBS News. The rabbi of the Shul where Leiby worshipped with his family cried from his very first word in Yiddish, quoting scripture as he tried to comfort the attendants, said ABC News. Family members then returned to their home, where Leiby lived with his parents and sisters, to grieve in private. The boy's burial will be in Laurel Park, N.J.

The day Aron was arrested - July 13 - was the man's 35th birthday. And it was also days before the boy's 9th birthday.

The Full Text of Levi Aron's Confession

The following is the full text of the confession of Brooklyn Boy Leiby Kletzky's killer as published by NBC New York on Thursday:

My name is Levi Aron... On Monday evening around 5:30 I went to my dentist, Dr. Sorcher, to make a payment for visit for exam routine.

A boy approached me on where the Judaica book store was. He was still there when went out from the dentist's office. He asked me for a ride to the Judaica book store. While on the way he changed his mind and wasn't sure where he wanted to go.

So I asked if he wanted to go for the ride - 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.

Due to traffic, I got back around 11:30 p.m. ... so I brought him to my house thinking I'd bring him to his house the next day. He watched TV then fell asleep in the front room. I went to the middle room to sleep. That next morning, he was still sleeping when I was ready to leave.

So I woke him and told him I'll bring him to his house... when I saw the flyers I panicked and was afraid. When I got home he was still there so I made him a tuna sandwich....

I was still in a panic ... and afraid to bring him home. That is when approximately I went for a towel to smother him in the side room. He fought back a little bit until eventually he stopped breathing.

Afterwards I panicked because I didn't know what to do with the body.... carried parts to the back room placing parts between the freezer and the refrigerator ...

... went to clean up a little then took a second shower. I panicked and .. Then putting the parts in a suitcase. Then carrying suitcase to the car ...placing in backseat on floor behind passenger side.

... drove around approximately around 20 minutes before placing it in the dumpster on 20th street just before 4th Avenue. Then went home to clean and organize.

I understand this may be wrong and I'm sorry for the hurt that I have caused.