Jury deliberating in Pittsburgh police shootings

By JOE MANDAK | June 25, 2011 | 4:45 PM EDT

PITTSBURGH (AP) — A jury has begun deliberating charges against a man accused of killing three Pittsburgh police officers who responded to his mother's 911 call about an escalating argument.

Allegheny County prosecutors say a mountain of evidence provided by 41 witnesses and 500 exhibits points conclusively at 24-year-old Richard Poplawski as the gunman.

But Poplawski's attorney is trying to convince a jury that reasonable doubt remains about whether Poplawski's mother, Margaret, was involved — even though she's never been accused of a crime in the April 4, 2009, incident. Prosecutors say no evidence suggests she had a role in the shootings.

If Poplawski is convicted of first-degree murder for any or all of the killings, the trial will enter a penalty phase in which the jury will hear evidence about his mental state, background and other factors before determining if he gets the death penalty or life in prison without parole.