A Montgomery County judge will decide this morning the fate of a Plymouth Township man accused of raping and murdering his girlfriend's 14-year-old daughter.

Judge William J. Furber, who presided over the nonjury trial of Mark Patrick O'Donnell, 48, said on Tuesday that he would announce his verdict today after reviewing evidence in the five-day trial.

O'Donnell admits strangling Ebony Dorsey on Dec. 7. She had been baby-sitting O'Donnell's daughter so he could spend the night doing drugs with the victim's mother, Danielle Cattie, 34, of Whitpain Township.

He concedes that he used cocaine and that he abused the corpse, stuffing it into a 20-gallon storage container, which he hid on a relative's property. But he denies sexually assaulting the Wissahickon High honors student.

Defense attorney Thomas C. Egan III said his client's "obviously aberrant, horrific, violent behavior" would not have occurred absent the drug abuse. O'Donnell did not take the stand. Egan said cocaine forced O'Donnell to "snap," rendering him too impaired to form the specific intent to kill required for a first-degree murder conviction.

Egan is seeking a third-degree murder conviction.

First Assistant District Attorney Kevin R. Steele, who prosecuted the case with Samantha Cauffman, strongly disagreed, arguing that O'Donnell's deliberate actions before, during and after the crimes made first-degree murder appropriate.

Steele suggested that the teen's asphyxiation, which the medical examiner testified could have taken up to six minutes, required O'Donnell to take off the girl's pajama pants, knot them twice, wrap them around her neck, and pull them tight, easily constituting intent.

If the judge finds O'Donnell guilty of first-degree murder and rape, the trial will proceed to the death-penalty phase to determine whether the sentence should be life in prison or execution.

A second-degree murder conviction would result in a sentence of life in prison, and a third-death murder conviction carries a 20- to 40-year sentence.

The judge could increase that time, however, by running some of the charges that O'Donnell has admitted, such as abuse of a corpse, consecutively.

O'Donnell is also a "possible suspect" in the May 2006 triple slaying of a Philadelphia family at their Port Richmond home, where O'Donnell had been assigned as a private-duty nurse.

Lt. Frank Vanore, a Philadelphia police spokesman, said that the case is still under investigation and that a grand jury prevented the department from commenting.

Contact staff writer Kathleen Brady Shea at 610-701-7625 or kbrady@phillynews.com.