A medical examiner has determined the cause of death of Leiby Kletzky, announcing Wednesday that the 8-year-old was first drugged and later smothered.

According to officials, Kletzky died from a combination of drugs including cyclobenzaprine (muscle relaxant), quetiapine (antipsychotic), hydrocodone (pain medication), and acetaminophen (Tylenol) followed by smothering.

The announcement detailing the child's cause of death comes within hours of an expected indictment in the case against Levi Aron, the man accused of murdering Kletzky.

Crime scene investigators continue to remove and analyze every shred of evidence they possibly can at Aron's home on East 2nd Street in the Kensington neighborhood in their effort to make the strongest possible case against Levi Aron and to figure out if he abused or even killed other children.

Aron, meanwhile, is in the inmate psych ward at Bellevue Hospital, undergoing psychological evaluations that are part of his attorney's defense that seeks to keep Aron, 35, in a mental health facility rather than have to go to prison if he's found guilty.

At his arraignment last week, Aron pleaded not guilty, despite confessing to detectives that he kept Kletzky at his apartment rather than getting him home, then suffocated the boy, dismembered his body and tried to dispose of some body parts in a dumpster.

Levi Aron's lawyer, Pierre Bazile, has said he'll pursue an insanity defense for his client. At Aron's arraignment last week, his lawyer said that his client was hallucinating and hearing voices. Prosecutors, however, are simply not buying it.

"Sometimes I wonder about what goes through defense lawyers' minds," the Brooklyn D.A., Charles Hynes, said after paying a visit to the Kletzky Family Tuesday while they sat shiva, the seven-day mourning period in the Jewish faith. He's said he's made a personal commitment to prosecuting the Levi Aron case to the fullest extent "in a way that is appropriate."

The insanity defense requires proof that a defendant not be able to distinguish between right and wrong. Prosecutors, however, have pointed out that since Aron has admitted to not contacting police when Leiby was lost, then keeping the boy in his custody, suffocating him and diligently working to cover up his crime, Aron knew full well that what he was doing was wrong. Therefore, prosecutors are expected to argue, the insanity defense does not hold up.

The unsealing of the indictment against Aron is expected Wednesday afternoon.