"Based upon the facts of this case and Mr. Harris' background his propensity for violence we wanted to give the jury the option to have the death penalty," he said in a telephone interview.
Harris, 27, is charged in the Feb. 21 pre-dawn killings of Kenneth Cherry Jr., a cab driver and cab passenger after police say he fired shots into Cherry's Maserati while driving a Range Rover on the Las Vegas Strip.
The Maserati crashed into a taxi cab that exploded, killing Michael Boldon, 62, Las Vegas; and passenger Sandra Sutton-Wasmund, 48, Maple Valley, Wash.
Harris is charged with the murder of all three. He's also charged with the attempted murder of Freddy Walters, a passenger in the Maserati who was shot along with Cherry but survived.
Police said Harris and Cherry had exchanged angry words at a casino valet stand before speeding with tires squealing up the neon-splashed Strip.
Tehran Boldon, the younger brother of Michael Boldon, told the Las Vegas Sun after Wednesday's filing that Harris has "shown no remorse, and he needs to be made example of."
"Hopefully it will send a message to people like him that think it's a game," he said. "I would hate to think that he could outlive me when I don't think he should be living at all."
Harris previously was arrested in 2010 in Las Vegas on charges of pandering, kidnapping, sexual assault and coercion. The charges were dropped, but a witness re-emerged after Harris' arrest this year and a jury indicted him in April on three counts of sexual assault and one count of robbery related to the 2010 arrest.
The district attorney's office considered this second charge when it decided to seek the death penalty, and also invited Harris' attorneys to present mitigating evidence.
"When you make a determination of whether or not to seek the death penalty, you look at the whole person the good and the bad," Wolfson said.
Wolfson has presided over a sharp decrease in the number of death penalty cases in Las Vegas.
The Clark County district attorney was averaging about 20 death penalty cases a year when Wolfson took the post in 2012. He dropped that number to five last year.
"My philosophy is that the death penalty should be sought in only the worst of the worst kind of cases," he said.