California authorities say DNA in two 1978 killings in Sacramento led to the arrest of a man suspected of being a serial killer tied to dozens of slayings and sexual assaults in the 1970s and '80s.

Sacramento County District Attorney Anne Marie Schubert told reporters Wednesday that the DNA helped solve the case in the last six days.

She said the "answer was always going to be in the DNA" and the connection came in the slayings of Brian and Katie Maggiore.

Sacramento County jail records show 77-year-old Joseph James DeAngelo was arrested overnight on two counts of murder cited in a Ventura County warrant.

FBI and California officials last year renewed their search for the suspect dubbed the East Area Rapist and announced a $50,000 reward for his arrest and conviction. He's linked to more than 175 crimes in all between 1976 and 1986 across ten counties. 

As he committed crimes across the state, authorities called him by different names. He was dubbed the East Area Rapist after his start in Northern California, the Original Night Stalker after a series of Southern California slayings, and the Diamond Knot Killer for using an elaborate binding method on two of his victims.

Sacramento County District Attorney Anne Marie Schubert said the case forever altered a time of innocence in the community. 

"For anyone that lived here in this community in Sacramento, the memories are very vivid," Schubert said. "You can ask everyone who grew up here -- everyone has a story."

In the last six days, DNA analysts at the crime lab offered up a break in the case, and a warrant was issued for two 1978 murders, Schubert said. 

"We all knew as part of this team that we were looking for a needle in a haystack, but we also all knew that the needle was there,"  Schubert said. "We found the needle in the haystack, and it was right here in Sacramento."

Jones said officials conducted surveillance on DeAngelo and used a discarded item to make the DNA match to the string of crimes.

A woman who was sexually assaulted by a man believed to be the East Area Rapist in 1976 and now lives in South Carolina tells The Island Packet newspaper Wednesday that she has been contacted by two detectives about an arrest.

Jane Carson-Sandle was attacked in her home in the Sacramento suburb of Citrus Heights. A home in that community belonging to a former police officer was being searched Wednesday by FBI investigators and police from several agencies.

Two neighbors who declined to give their names said authorities arrived at the scene before midnight. Sacramento County Jail records show the man who lives at the home was booked into the facility at 2:30 a.m. on suspicion of murder.

"48 Hours" investigated the case in the episode, "The Golden State Killer. The late true crime writer Michelle McNamara, the wife of comic Patton Oswalt, was on the hunt for the killer and writing a book on the case at the time she died on April 21, 2016. The broadcast featured Oswalt's first in-depth television interview about his wife's reporting on the case. 

(The Associated Press, CBS News contributed to this report.)