DURING HIS closing argument Tuesday in the trial of Sabina Rose O'Donnell's alleged killer, a city prosecutor seized on DNA evidence that linked Donte Johnson to her 2010 rape and murder.

A defense attorney, for his part, said that the "feeble-minded" Johnson may have been "one can short of a sixpack" but that he was not guilty.

The arguments, delivered to a packed Philadelphia courtroom, were followed by jury instructions from Common Pleas Judge Glenn Bronson. The jury deliberated for about two hours before going home for the day.

Johnson, 20, is accused of stalking the 20-year-old Northern Liberties waitress as she rode a borrowed bicycle home on Girard Avenue early on June 2, 2010. Johnson allegedly dragged her from the front of her apartment building at 4th Street and Girard Avenue to a rear lot, where, prosecutors contend, he tore off her clothes, beat, raped and strangled her with her bra strap.

Despite what prosecutors allege was a large quantity of Johnson's semen found in and around the victim's body, defense attorney Gary Server railed against the accuracy of that evidence, and against DNA evidence in general. Mistakes can be made in the lab when DNA is tested, he said, and the prosecution presented no evidence that the machines used to process his client's sample had been working properly.

"DNA science is one of those sciences that has the tendency to mislead you," said Server.

He also told the jury to disregard the police statement in which Johnson had confessed to dragging O'Donnell to the vacant lot and raping her. He said the language and syntax in the statement could not have been made by Johnson, whom a defense expert witness testified has brain damage and functions at the intellectual level of an 11-year-old.

"Justice for Sabina doesn't mean convicting the wrong person. That would not be justice. We need to find the right person who did this," Server said.

"How dare anyone talk about justice for Sabina!" Assistant District Attorney Richard Sax said during his closing argument. "Don't you get it? Don't you understand, there will never be justice for Sabina."

Sax said it was nearly statistically impossible for anyone but Johnson to have been the person whose DNA was found.

He said the multiple lies Johnson told to police before confessing are an indication that he does not have brain damage and is not mentally handicapped, as his attorneys asserted.

"There are no words that adequately describe the monstrous acts of Donte Johnson," Sax said. n

Mensah M. Dean, contact him at 215-568-8278 or deanm@philly.com.