A Carbon County man and woman, charged with plotting to kill his grandmother, pleaded guilty in the county court on Tuesday and are facing state prison terms at the time of sentencing.

Amber Lynn Steigerwalt, 20, and Jacob Gordon Wertman, 24, both of Lehighton, entered pleas before Judge Joseph J. Matika.

Steigerwalt pleaded to one count of aggravated assault for her part in the Sept. 24, 2012, incident in East Penn Township.

Wertman pleaded to one count of criminal conspiracy to commit aggravated assault for his part in the plot to kill his grandmother.

Wertman also pleaded to one count of possession with intent to deliver a controlled substance-heroin for an incident that occurred on May 27, 2012, following a traffic stop.

State police at Lehighton charged the two with attempting to kill Wertman's grandmother, Marge Wertman, at her residence in Ashfield in the township.

During the plea hearing Tuesday, District Attorney Gary F. Dobias said the two met at another location and planned to kill Mrs. Wertman and her husband, allegedly for inheritance money. The defendant was living with his grandmother at the time.

Dobias said when Marge Wertman returned home from work she saw her grandson in the kitchen area. She spoke to him but he said nothing. She then began to walk away when Steigerwalt came up behind her and stabbed her at least twice in the neck.

Mrs. Wertman was able to fight back and grabbed Steigerwalt by the throat and began to choke her, Dobias said. Steigerwalt managed to free herself and fled the home.

Mrs. Wertman was bleeding heavily and attempted to call 9-1-1 but her grandson interfered. She then asked him to take her to a hospital but he at first refused. Dobias said Jacob Wertman eventually did take his grandmother to the Lehighton hospital for treatment. She has since recovered.

Wertman was arrested on the drug count following a traffic stop by state police. He was a passenger in the car stopped by troopers. Found in the vehicle were 140 bags of heroin.

In a plea agreement with the DA's office, Steigerwalt is facing a state prison term of four and a half to 10 years. Wertman faces the same prison term plus an addition six to 12 months for the drug charge for a total of five to 11 years.

Dobias noted that the victim agreed to the plea agreement. Dobias also added that both defendants were using heroin heavily at the time.

Matika accepted the pleas and deferred sentencing ordering the adult probation office to prepare a presentence investigation report. Matika told both defendants he was not a party to the plea agreement. He said he will decide if he will go along with the recommended sentence after reading the PSI report.

Both defendants have been in prison since their arrests for the incident.