A Contra Costa County jury is now weighing the fate of the man who murdered his former girlfriend and her male friend on the Richmond-San Rafael Bridge toll plaza.

Nathan Burris, 49, who is representing himself in Contra Costa County Superior Court, took the stand in Martinez Thursday to present closing arguments in the penalty phase of his capital murder trial.

The jury that convicted him last week on murder charges with special circumstances for fatally shooting Deborah Ross, 51, of Richmond and 58-year-old Ersie "Chuckie" Everette of San Leandro on Aug. 11, 2009 began deliberations this afternoon to decide whether to sentence Burris to life in prison or to death.

His testimony this morning came after closing arguments by Chief Assistant District Attorney Harold Jewett, who reminded the jury that the district attorney's office is seeking the death penalty in the case.

Jewett advised the jury that they are tasked with reaching the most just verdict, regardless of their own views on the death penalty or the perceived wishes of the family or of Burris himself.

Whether or not the death penalty is ever carried out, depending on state law at the time, the prosecutor told the jury that their condemnation of the defendant should "echo through the depths of time."

Jewett Thursday described Burris as a "psychopathic killer" and a sociopath who is devoid of a conscience.

"Nathan Burris is motivated by hate and he has been for most of his life," he told the jury this morning. He reminded them of an incident in 1993 when Burris allegedly threatened to kill managers at an Oakland housing complex where he had just quit his job if they failed to deliver his last check within three days.

During testimony on Wednesday, Burris also spontaneously confessed to committing a string of armed robberies at Walgreens pharmacies in San Francisco during the mid-1990s -- a factor that Jewett said the jurors have the right to consider when determining a sentence.

The defendant himself testified earlier in the trial that his anger and hatred for Ross and Everette, the man Burris believed she was dating, spurred him to go to the Richmond-San Rafael Bridge toll plaza where Ross was working as a toll-taker during rush hour on Aug. 11, 2009. There, he shot and killed Everette as he sat in a pickup truck parked at the toll plaza, then ran over to the tollbooth where Ross worked and opened fire on her.

Thursday, he reiterated his oft-repeated stance that it's all the same to him whether he is sentenced to death or to life imprisonment, and that he is ready to accept his fate.

"I'm walking the plank, and it's my plank to walk," he said from the witness stand.

Burris, who has called California capital punishment laws "a joke," said today that he doesn't fear getting the death penalty.

"If I was in Texas, I'd be terrified," he said, laughing. "The death penalty means nothing to me but time to hang out and do whatever I'm going to do."

"If it was up to me, and you asked me what I'd prefer -- I'd say the death penalty...the main reason is because I deserve it," he said.

But Jewett said that he believes Burris is indeed afraid of death and would not be smiling and laughing as he has done throughout the trial if he thought his death was imminent.

Regardless of the defendant's feelings about his fate, the prosecutor said, the harm he has caused his victims and their loved ones and his callous disregard for their lives warrants the forfeiture of his own.

Jurors deliberated for nearly two hours following closing arguments this afternoon and are set to continue deliberations on Monday.