A man has been charged with tampering with evidence in the case of a woman presumed killed by the married man she had been seeing, authorities said Friday.

The Mercer County prosecutor's office would not release details on how they believe John A. Russo Jr. of New York City is connected to the case of Amy Giordano's death.

The evidence tampering charges against Russo were announced just one day after Rosario DiGirolamo was charged with murdering Giordano, 27. Her body has not been found.

Russo, 43, has been advised of the charge and is expected to be formally served with the complaint in the next few days, authorities said. He faces a maximum of 18 months in prison if convicted, according to prosecutor's office.

A phone listing for Russo could not be found. Casey DeBlasio, a spokeswoman for prosecutor's office, said she did not know whether he had a lawyer.

DiGirolamo, 33, was having an affair with Giordano at the time of her disappearance. She vanished in June two days before DiGirolamo abandoned their 11-month-old son in the parking lot of a Delaware hospital.

DiGirolamo pleaded guilty in November to reckless endangerment and child abandonment. The child is now in foster care.

DiGirolamo's lawyer, Jerome Ballarotto, has said he is prepared to defend his client against the murder charge.