HOUSTON -- The stepson of a Houston police officer who was murdered by an illegal immigrant told a jury Wednesday about his mother's reaction to the killing, KPRC Local 2 reported.

Juan Leonardo Quintero, 33, was found guilty last week of capital murder in the death of Officer Rodney Johnson. Quintero was in the back seat of Johnson's patrol car after he was arrested for driving without a license on Sept. 21, 2006.

Reginald Johnson, a 16-year-old Elkins High School student, said he loved working out with his stepfather and fondly remembers watching him dance to James Brown songs.

He said his mother learned of her husband's death while she was sitting the stands at his football game. He said he noticed his mother was suddenly crying.

"Now I don't have a man to help shape me into a better man," Reginald Johnson told the jury.

Reginald Johnson's 21-year-old sister testified Tuesday that her boyfriend proposed to her this week and she is saddened that he was not able to ask her stepfather for her hand in marriage and that he is not here to walk her down the aisle.

Quintero's mother, brother and aunt took the stand Wednesday in hopes of sparing the killer's life.

Quintero confessed to the murder, but said he shot Johnson because he was afraid of being arrested and the possibility that he could be deported to Mexico because he was in the United States illegally. He pleaded not guilty by reason of insanity, claiming that a childhood brain injury caused him to not be able to reasonably react to some circumstances.