A man charged with murdering his mistress by beating her over the head with a metal tool once tried to kill the woman by drugging her with sleeping pills, a lawyer for an alleged accomplice claims.

George Vomvolakis said murder suspect Rosario DiGirolamo drugged Amy Giordano with pills some time before she went missing last June 7, but the drugs he slipped into the woman's drink only made her groggy.

Vomvolakis represents John A. Russo Jr., the Staten Island home improvement store manager authorities say helped his friend, DiGirolamo, dispose of Giordano's body after killing her and hacking up the corpse.

Vomvolakis says DiGirolamo confided the failed murder attempt to Russo, who later showed him the remote Staten Island pond where a body could be discarded.

DiGirolamo's lawyer, Jerome Ballarotto, did not return phone messages seeking comment Thursday. He told The Times of Trenton, which first reported the lawyer's claims Thursday, that DiGirolamo is innocent and that the sleeping pill accusation is "absurd."

Human skeletal remains believed to be the Mercer County woman's were found in a shallow pond on Staten Island and are undergoing genetic testing. Authorities searched the pond after getting information from Russo.

DiGirolamo, charged with murder, is jailed on $1 million bail. Russo is to be arraigned Friday on an evidence tampering charge.

Vomvolakis said Russo will plead not guilty and is expected to be released.

The married DiGirolamo, 33, and divorced Giordano, 27, had a long-standing affair and had an 11-month-old son together. He paid the $850 monthly rent on her apartment above a nail salon while living in a big, suburban house with his wife and son, who was the same age as the child he fathered with Giordano.

Details about the case have steadily emerged from Vomvolakis and prosecutors since DiGirolamo's arrest last month.

Authorities believe Giordano was killed in her Hightstown apartment. Her body was then dismembered, and at least the torso was dumped in a suitcase in the pond where divers found the remains on Easter Sunday.

Vomvolakis said the victim's head may have been disposed of separately, based on a conversation between DiGirolamo and Russo in which the suspect allegedly recounted a Sopranos episode where mobsters dumped a head and body in separate locations to avoid identification.

DiGirolamo earlier pleaded guilty in Delaware to abandoning the couple's toddler in a hospital parking lot there. Ballarotto has said DiGirolamo dumped the child after Giordano fled, but did not leave the lot until someone found the boy and he was assured of his safety.