Mark O'Donnell bombarded himself with hundreds of images of online pornography within minutes of murdering 14-year-old Ebony Dorsey, prosecutors in his Montgomery County murder trial tried to prove yesterday.

But perhaps the most disturbing mouse click he made in those early morning hours on Dec. 7 took him to a pornography Web site called "Ebony Internal," a site that shared a name with his alleged victim, according to court testimony.

O'Donnell, 48, of Plymouth Meeting, faces the possibility of the death penalty if he is convicted of first-degree murder.

His fate rests in the hands of Montgomery County Judge William Furber, who is presiding over the nonjury trial.

O'Donnell has admitted killing Ebony after smoking crack all night at the Ambler home of Danielle Cattie, Ebony's mother and O'Donnell's girlfriend.

Ebony had been taken to O'Donnell's estranged wife's apartment in Plymouth Township to baby-sit his 4-year-old daughter. O'Donnell's estranged wife, Tameika, was out of town on business at the time.

After the crack binge with Cattie, O'Donnell said he went back to the apartment, found Ebony changing his daughter's diapers and thought she was molesting the girl, a claim which police said was unfounded.

In his drug-fueled rage, O'Donnell strangled and beat Ebony to death, then stuffed her body in a 20-gallon plastic storage bin and hid it outside his nephew's house in Blue Bell, where it was found two days later.

Montgomery County Detective Greg Kuter, who works in the computer unit of the major-crimes division, testified that he examined a computer at O'Donnell's apartment, where Ebony was killed.

He said that from 10 p.m. Dec. 6 to about 2 a.m. Dec. 7, the activity on the computer was typical for a teenager - visits to MySpace and photographs of famous musicians.

The electronic activity stopped about 1:50 a.m. About 5:40 a.m., about the time O'Donnell is alleged to have returned to the apartment, the computer was activated again. In a 10-minute period, 432 images of pornography were viewed on the computer, Kuter said.

Defense attorney Thomas C. Egan III said that the retrieved photos included every image on every site visited and that the numbers don't necessarily correlate to the number of pictures that were viewed individually.

Forensic pathologist Dr. Ian Hood testified that exterior rips and interior bruising on Ebony's anal and vaginal regions suggested she had been raped and sodomized before her death. The wounds, one of which was five inches deep, "slightly favor" that she had been violated with an inanimate object more so than a penis, Hood said. No traces of DNA were uncovered during the autopsy.

Hood also testified that Ebony most likely remained alive for up to two minutes while she was being strangled with her own pajama pants and was forcibly gripped by a human hand.

Because of evidence of an impact on the right side of Ebony's head, the cause of her death was ruled as both blunt trauma and asphyxiation. *