A Glen Burnie man who told police that he would not have killed his father and wounded his stepmother had he not been so high on PCP pleaded guilty yesterday to the crime and agreed to the maximum sentence.

The only issue that remains for the sentencing hearing in December is whether Charles Martin Grierson can win a judicial recommendation for incarceration at the Department of Public Safety and Correctional Service's sole facility that focuses on treatment.

Grierson, 27, pleaded guilty before Anne Arundel County Circuit Judge Pamela L. North to second-degree murder and felony assault in the Jan. 22 fatal stabbing of his father, Fred Charles Grierson, and the wounding of his stepmother, Deborah Grierson, at their Glen Burnie home. Relatives and friends watched the proceeding in silence.

Grierson, wearing a dark suit, spoke only to agree to a plea that will result in the 30-year sentence. Because of the high level of PCP in his system when he killed his father, a charge of first-degree murder was dropped.

Grierson's lawyer, John H. Robinson III, said outside of court that "there was very aberrant behavior on [Grierson's] part leading up to these events." He said he would not discuss the matter until sentencing.

After the killing, friends said Grierson had a PCP problem and in the days before the stabbings had been acting in a peculiar manner. The drug has been linked to unpredictable and violent behavior.

At yesterday's hearing, Assistant State's Attorney Laura S. Kiessling said that Grierson made an unprovoked attack on a girlfriend at his parents' home the day of the killings. His father and stepmother tried to intervene, and Grierson grabbed a kitchen knife and stabbed his stepmother, who fled to neighbors, Kiessling said.