The arrest and charges were announced Tuesday at county headquarters, but the case against Naso has been a year in the making.
When Naso is formally charged with murder in Superior Court on Wednesday, it will be exactly one year to the day since his arrest at his home in Reno in 2010.
"During that arrest, investigators found items by Mr. Naso that implicated him in multiple murders of young women," said Marin County District Attorney Ed Berberian.
Berberian told reporters the victims are Roxene Roggasch, whose strangled body was found in Marin in 1977, Carmen Colon, whose body was found in Port Costa in 1978, and Pamela Parsons and Tracy Tafoya, both found in Yuba County in 1993 and 1994, respectively.
Berberian told ABC7 that investigators found photos and writings that tied Naso to the killings. We also know the self-employed photographer was on probation from a theft conviction, and when his parole officer visited Naso at his house, he found him with a gun. That was enough to send Naso to jail for the past year.
"Marin County sheriff's detectives arrested Naso in South Lake Tahoe on Monday upon his release from the El Dorado County Jail where he was in custody over the past year on unrelated charges," said Berberian.
The first of four victims was found alongside Sir Francis Drake Boulevard just west of Fairfax. She was 18-year-old Roggasch of Oakland. And although it didn't come up in Tuesday's press conference, investigators couldn't help but notice that each of the victims had the same double initial -- Roxene Roggasch, Carmen Colon, Pamela Parsons, Tracy Tofoya. Now authorities in Rochester, New York are looking at a series of unsolved murders with that same characteristic.
Naso grew up in the Rochester area, and though he moved out west in 1969, authorities believe he likely traveled back to Rochester from time to time.
Currently Naso is facing charges for just the four murders in California.
"Naso will be presented with a criminal complaint when he appears that lists the four charges, the four murder counts that I've named, each carrying a special circumstance for multiple murder," said Berberian.
That means that the district attorney will be seeking the death penalty if Naso is convicted. He is due to be arraigned on charges Tuesday afternoon in Marin County Superior Court.
