'Golden State Killer' suspect arrested, identified as former police officer

She said DNA was crucial in identifying the suspect.

Sacramento County Sheriff Scott Jones said DeAngelo was detained Tuesday in "a perfectly executed arrest."

Ventura County District Attorney Greg Totten said at the press conference capital murder charges were filed against DeAngelo for the 1980 murders of Lyman and Charlene Smith in Ventura.

At the press conference, Orange County District Attorney Tony Rackauckas cited August 1980 murders of Keith and Patrice Harrington in Orange County, Calif.; the February 1981 murder of Manuela Witthuhn in Irvine; and the May 1986 murder of Janelle Cruz, also in Irvine, in relation to the case. Rackauckas said further charges were expected in Orange County.

“Not all the cases had DNA, but many did,” Alameda County District Attorney Nancy O'Malley said in Wednesday's news conference. O'Malley said all of the cases were tied together by either the M.O. or DNA.

Schubert said the suspect was linked through DNA using current and innovative techniques, but would not elaborate on how the suspect was targeted when asked. She said the latest developments occurred in the last six days.

Sheriff Jones said evidence came from "a discarded DNA sample."

Sheriff Jones said the investigation is still active, and that warrants were currently being served and interviews conducted “as we speak.”

Jones said authorities had been surveilling DeAngelo. When DeAngelo came out of his residence, a law enforcement team took him into custody, and he seemed surprised, according to Jones.

DeAngelo is a former Auburn Police officer who was fired in 1979 for shoplifting dog repellant and a hammer from a store in Citrus Heights, according to the Auburn Journal.

UPDATE 8:56 a.m. PT:

Sources confirm that the Sacramento County Sheriff's Department is working a significant break in the search for the East Area Rapist, KTXL reports.

A law enforcement source has named 72-year-old Joseph James DeAngelo as the suspect arrested in the decadeslong case. The department said it hopes to release further information Wednesday.

DeAngelo was arrested at his Citrus Heights home, and was booked into jail on two counts of murder, KTXL reports.

WATCH: Unsolved: California's 'East Area Rapist' remains at large - CWD

Neighbors told FOX40 they saw DeAngelo as a "nice guy" but was occasionally prone to profane outbursts heard throughout the neighborhood.

Police believe the East Area Rapist or Golden State Killer was responsible for 12 homicides, almost 50 rapes and 120 home burglaries that spanned a decade starting in the late 1970s in Sacramento County.

"It is the most prolific unsolved serial killing case probably in modern history," said Sacramento County District Attorney Anne Marie Schubert.

Sacramento District Attorney Anne Marie Schubert and Sheriff Scott Jones are expected to hold a press conference at 12 p.m. on Wednesday.

The Sacramento Bee reports FBI agents and law enforcement from Sacramento County and Southern California were outside a home this morning in Citrus Heights near the city border with Roseville. Joseph James DeAngelo has lived there for at least two decades, public records show.

DeAngelo, 72, is listed in Sacramento County jail records as being booked early this morning on two counts of murder from a Ventura County Sheriff's Department warrant, the Bee reports.

via KTXL:

SACRAMENTO -- (KTXL) -- Sources confirm that the Sacramento County Sheriff's Department is working a significant break in the search for the East Area Rapist.

A possible arrest in the decades-long case may have been made. The department said it hopes to release further information Wednesday.

Police believe the East Area Rapist or Golden State Killer was responsible for 12 homicides, almost 50 rapes and 120 home burglaries that spanned a decade starting in the late 1970s in Sacramento County.

CWD: Unsolved: California's 'East Area Rapist' remains at large

“It is the most prolific unsolved serial killing case probably in modern history,” said Sacramento County District Attorney Anne Marie Schubert.

FOX40's own “Exposed: East Area Rapist” podcast covered the cold case through interviews with victims, their families and the original investigators.