The video is graphic and difficult to watch. A burly man pushes his way into a suburban home where a mother and her 3-year-old daughter are watching television, then punches and kicks her for several minutes, at one point throwing her down a flight of stairs.

It's what appears much later on the video, after Millburn police responded, that may allow the man charged with the attack to go free.

That's when a white officer is overheard using racial slurs to describe the attacker, who is black. Officer Colin McMillan admitted during testimony in May that he made the remarks. He also testified he didn't question defendant Shawn Custis and didn't collect evidence, though he was present at the man's arrest and filed evidence collected by other investigators.

The specter of potential police bias has hung over the trial of Custis, the 45-year-old Newark man on trial for attempted murder, robbery and other crimes for the brutal 2013 home invasion caught on a home security video camera, or "nanny cam."

A jury of nine blacks and three whites began deliberations Tuesday, weighing whether to believe Custis' defense attorney's claim that his client was framed by racist cops, or prosecutors' contentions that bias didn't play a part and that they were led to Custis by several people who identified him after seeing the video on television.

Prosecutors showed the video to jurors at the beginning of Custis' trial; when Assistant Essex County Prosecutor Jamel Semper showed it again later in the trial, two female jurors held their hands over their eyes.

Because of the video, the officer's slur could hurt the prosecution's case but not necessarily lead to an acquittal, said Ben Barlyn, a former Hunterdon County prosecutor who worked on the manslaughter case of former NBA star Jayson Williams.

Williams' attorneys tried unsuccessfully to have his convictions thrown out after it was revealed a detective not directly involved in the investigation used a racial slur.

"In what would otherwise be a case with very strong evidence of an egregious crime, it's a headache for the prosecutor but not necessarily a fatal headache," Barlyn said, referring to the Custis case. "The prosecutor's concern would be that the jury would disregard evidence of the defendant's conduct and send a message that the institution must be held accountable by nullifying the verdict. And that's a very powerful message."

Custis was arrested about a week after the crime in New York City, after police say they received calls from several women saying they recognized him. Prosecutors also presented evidence that blood on jeans found in his apartment came from the victim, who testified but whose name has not been released.

Defense attorney John McMahon argued that the investigation was tainted by racial animus and that police ignored evidence that could have pointed to other suspects. He also said the video quality isn't good enough for a positive identification of Custis.