The jury in Mr. Velez's murder trial is expected to begin deliberating Wednesday.

WSJ: Officer's Murder Accidental, Jury Finds

Mr. Velez's attorney, Damien Brown, said his client has maintained he knew nothing of the plot, but Mr. Taub told the jury the driver became an accomplice to murder when he asked for a cut of the proceeds after learning of the robbery plan, agreed to be a lookout, then fled.

WSJ: Trial Opens in Slaying of Officer

Brousseau, the aunt, also spoke to HLN's Velez-Mitchell, saying she believes her nieces must have been taken by a stranger.

CNN: STORY HIGHLIGHTS