By unanimous verdict, a jury said Andrew Urdiales was guilty of killing the victims in Orange, Riverside and San Diego counties. He had previously been convicted in the deaths of three women in Illinois.
Urdiales' Southland killing spree began in Mission Viejo on Jan. 18, 1986, prosecutors said.
"On that day, he left Camp Pendleton with, in his words, a big 'ol hunting knife," senior Deputy District Attorney Matt Murphy told jurors in a Santa Ana courtroom during closing arguments.
Urdiales stabbed and killed 23-year-old college student Robbin Brandley while she was walking to her car at Saddleback College. Later, while stationed at Marine Corps Air Ground Combat Center Twentynine Palms, Urdiales shot and killed four other women in the 1980s and 1990s. Mary Ann Wells was killed in San Diego, while Julie McGhee and Denise Maney were found in the desert areas of Riverside County. Tammie Erwin, the youngest victim at just 18, was also found dead in Riverside County.
Brandley's father, Jack Reilley, said he's waited for this day for 32 years.
"I've never hated anyone before, ever in my life, but, boy, sitting there looking at him, I felt pure hate," he said.
Prosecutors called Urdiales a misogynist who enjoyed preying on women. Brandley was stabbed 41 times, and Urdiales later confessed to killing her. Jurors also found Urdiales guilty of special circumstances murder.
Defense attorneys argued that Urdiales was born with brain damage from fetal alcohol spectrum disorder and had a difficult upbringing.
Urdiales is already serving a life sentence for murdering three prostitutes in Chicago.
The DA's office will seek the death sentence in the California trial's penalty phase, something Tammie's father, Charles Erwin, said he supports.
"Because of the nature of his crimes, the way he did the girls, like they were just trash, just throw them away," he said.
That phase of the trial is expected to begin next Tuesday.