The jury took just five and a half hours to find him guilty and just three hours to sentence him to death. It followed a compelling closing argument by prosecutors that brought tears to the courtroom.
The prosecution quoted from Naso's own diary -- his long history raping women, starting when he was a teenager. He committed the first murder in this case when he was 43, the last when he was 60.
Naso was convicted of killing Roxene Roggasch in Marin County, then, Carmen Colon in Contra Costa County, and Pam Parsons and Tracy Tafoya in Yuba County. In the penalty phase, prosecutors added evidence of two more murders -- Sara Dylan in Nevada County and Sharieea Patton, also in Marin County.
With such overwhelming evidence, the jury decided Naso should be put to death.
"The evidence, we believe, was very compelling showing his involvement in this case and also what the punishment should be," Marin County District Attorney Ed Berberian said.
After the verdict, Naso released a statement through his advisory counsel, saying, "I am pleased that the jury listened to my mitigation arguments. I want to help others in prison. I am on the threshold of a new life and will make the best of it."
The daughter of victim Carmen Colon spoke exclusively to the ABC7 News I-Team about the jury's decision.
Dan Noyes: "What do you think about that?"
Rachel Smith: "I think we're wasting money, it's not worth it."
Dan Noyes: "The appeals and all?"
Rachel Smith: "Exactly, exactly."
But her sister is pleased Naso received a death sentence.
"He took something away from me 35 years ago, and finally justice is served for that," Angelique McDonald said.
Attorney Robert Bryan specializes in death penalty cases and he blasted the 79-year-old's decision to act as his own attorney.
"That's just the height of stupidity, bad judgment and arrogance," Bryan said.
Bryan says Naso now can't argue that he had "ineffective counsel" in the automatic appeal that takes place, and that process can last more than 20 years. So, Bryan points out, no matter what the penalty -- life in prison without the possibility of parole or death -- the net effect is the same.
"I think one would bet on this, that he'll die of either old age or poor health or maybe suicide certainly before he gets anywhere close to the death chamber, being executed," Bryan said
Bryan says it would be highly unusual for the judge to overturn the will of the jury. There's a hearing on Friday to set a date for formal sentencing.