The two men charged in the May 3 killing of police Sgt. Stephen Liczbinski - one of them a boxer whose attorney said may be brain-damaged - yesterday asked to be tried separately because the defense of one might undercut the other.

Gary S. Server, the attorney for Levon Warner, told Philadelphia Common Pleas Court Judge Benjamin Lerner that he was considering a defense that Warner had brain damage that made him vulnerable to the influence of codefendant Eric DeShann Floyd.

Warner, 40, was a heavyweight boxer active between 1993 and 2007, with a record of six wins, five losses and two draws. Server said he is investigating whether Warner's ring career, in which he was knocked out three times, might have left him impaired.

Such a defense, known as "diminished capacity," could be used to convince a jury to find Warner guilty of a lesser degree of murder than first-degree, which carries a penalty of death or life in prison without parole.

But using the defense, Server said, would also further incriminate Floyd because of Warner's statement to police after his arrest in the Liczbinski shooting.

Lerner did not rule on the severance motion. He set another hearing for Jan. 7 and asked Assistant District Attorney Mark Gilson, Server and Floyd's defense attorney, William L. Bowe, to submit legal briefs on the issue.

The courtroom was packed beyond capacity, with about 80 police officers as well as Liczbinski's widow, Michelle, their three children, Matt, Steve and Amber; and brother Martin Liczbinski, a lower Bucks County firefighter.

Michelle Liczbinski said afterward she did not wish to comment.

Liczbinski, 39, died of multiple gunshot wounds after pursuing a getaway vehicle that left the robbery of a bank branch inside a Port Richmond supermarket.

Server said Warner's statement says Floyd, 34, who allegedly drove the getaway car, complained that he could not shake Liczbinski. Floyd allegedly turned to Warner, ordered him to pass the high-powered Chinese SKS rifle to backseat passenger Howard Cain, 33, and said: "Bang him."

Police allege that Floyd stopped the stolen Jeep at Almond and Schiller Streets and that Cain jumped out and began firing at the officer. Cain himself was shot and killed by police after the trio split up and fled on foot.

Lerner yesterday granted defense motions and dismissed attempted murder charges against Floyd and Warner involving witnesses menaced with the rifle during the bank robbery and escape.

The judge also denied one defense motion and held for review another dealing with what are known as "aggravating factors" involved in the shooting. Such factors can be used by the prosecutor after a first-degree murder verdict to argue to the jury that the death penalty is justified.

Gilson said the trial, or trials, of the two men would not take place until some time in 2010 because of the heavy court-system caseload. Also pending are separate trials for three others accused of helping Floyd elude police in the week after Liczbinski was killed.

Contact staff writer Joseph A. Slobodzian

at 215-854-2985 or jslobodzian@phillynews.com.