AURORA, Colo. -- Prosecutors in the death penalty trial of Sir Mario Owens rested their case Thursday afternoon, ending their case with emotional testimony from the mother of one of the victims.

Prosecutors rested their case in the death penalty trial of Sir Mario Owens after emotional testimony from the mother of one of the victims.

Christine Wolfe told jurors that her daughter Vivian was her best friend.

Wolfe and her fiancee, Javad Marshall-Fields, were ambushed in Fields' car in June 2005, just days before he was scheduled to testify in the murder trial of Greg Vann.

Holding back tears, Wolfe told jurors that she never knew that Marshall-Fields had been threatened, but that her daughter would have insisted that he testify because she always knew the difference between right and wrong.

After testifying, Wolfe told 7NEWS that she took the stand for her daughter and said too many people are afraid to stand up for the truth.

Wolfe, in essence, helped solve the mystery of who may have killed her daughter, because one of the key witnesses said he came forward after seeing the two victims' mothers on television pleading for witnesses to step forward.

Owens defense team will begin presenting its case Friday morning.

His attorneys said in opening statements that the key witnesses against him all have criminal records and shaped their stories to please prosecutors who in exchange gave them plea bargains.

Owens is already serving a life sentence for the murder of Gregory Vann at Lowry Park in Aurora on July 4, 2004.

If convicted, jurors will decide if Owens should be sentenced to death.