STOCKTON (KTXL) -- The Stockton Police Department has made an arrest in a four-year-old cold case. Investigators said a 76-year-old man has been arrested for the murder and rape of 84-year-old Hazel Dingman.
Investigators said Alvin Guy is a registered sex offender from a 1991 case out of California involving a minor.
In Susan Trinchero's arms is a picture of her late mother.
"It's just so unbelievable," Susan Trinchero, Dingman's daughter said. She was well-loved, friendly, good-hearted and greatly missed.
"My mother was 84 years old and the sweetest woman in the world," she explained.
After four years of not knowing who killed her, Dingman's family is finally getting some answers.
"This is a joyous, joyous day for the Dingman-Frolicker family," Trinchero exclaimed.
Related: Other notable cold cases:
Notable cold cases and unsolved murders throughout history
Arrest made in cold case murder, rape of 84-year-old woman
In June 1893 Lizzie Borden stood trial, later acquitted, for killing her father and stepmother with an ax. (Photo via Bettmann/Getty Images)
Foreboding Kingsbury Run, shunned by the timid as the legend of its murders has grown, is indicated on this map by dots locating 10 of the 11 torso murders which have occurred there since Sept. 23, 1935. Police, delving into the lives of the mad murderer's victims, hope to uncover clues which will end the periodic killings. Discovery of photo negatives in the belongings of Edward Andra Ssy, first victim, show Andra Ssy in a strange room which, if identified, may provide a live lead, police believe. As the map shows, the murderer departed only twice from his custom of assailing victims in Kingsbury Run or adjacent Cuyahoga river valley.
Bucks Row, now Durward Street, east London, where the body of Mary Ann Nichols, victim of Jack the Ripper, was found lying across the gutter. (Photo by Hulton Archive/Getty Images)
Head shot of aspiring actress Elizabeth Short, a murder victim nicknamed the Black Dahlia (Photo via Bettmann/Getty Images)
UNITED STATES - JUNE 26: Daily News front page dated June, 16, 1990, Headline: IS HE THE ZODIAC?, Police sketch of man who approached latest victim in Central Park last Thursday and asked him his birth date., June 26, 1990 . , Zodiac Killer. , Heriberto Seda. Headlines. IS HE THE ZODIAC ?, (Photo by NY Daily News Archive via Getty Images)
U.S. labor leader Jimmy Hoffa is photographed at the Greater Pittsburgh Airport, Pennsylvania in this April 12, 1971 file photograph. Hoffa was switching planes from San Francisco, and was returning to the federal prison in Allenwood, Pennsylvania. Hoffa was let out of prison to visit his wife, who had been hospitalized with heart problems. FBI teams on May 25, 2006 sifted by hand through dirt from a chest-deep hole in the ground in an intense search for the body of Jimmy Hoffa three decades after his disappearance. Hoffa was last seen outside a Detroit-area restaurant where he was to meet New Jersey Teamsters' boss Anthony "Tony Pro" Provenzano, a member of the Genovese crime family, and a local Mafia captain, Anthony "Tony Jack" Giacalone. Hoffa was declared dead in 1982, and numerous books about his life have pinned his disappearance on mobsters who murdered him because they did not want him interfering with their close ties to the union. B/W ONLY REUTERS/Jerry Siskind
The site where 6 year old JonBenet Ramsey was killed in Boulder, Colorado, 1996. (Photo by Karl Gehring/Liaison)
Black car in which rapper Tupac Shakur was fatally shot by unknown driveby assassins as he was riding w. friend Death Row records. pres. Marion Suge Knight, who survived shooting, behind police tape at crime scene (Photo by Malcolm Payne/The LIFE Images Collection/Getty Images)
Los Angeles Police detectives released this composite drawing March 27 of the man they believe killed rap star Notorious B.I.G. in Los Angeles recently. The suspect, a black man in his early 20's with close-cropped hair, was wearing a bow-tie the night of the drive-by killing. Investigators have set up a toll free number for the public to call with any information about the suspect.
Donna Norris poses next to a photo of her daughter Amber Hagerman, January 4, 2011, who was kidnapped 15 years ago while riding a bicycle near Norris mother's home in Arlington, Texas on January 13, 1996. (Richard W. Rodriguez/Fort Worth Star-Telegram/MCT via Getty Images)
Discover More Like This
BACK TO SLIDE
The Stockton Police Department arrested Guy for murder and rape. Officers took the registered sex offender into custody Wednesday in Las Vegas. Chief Eric Jones said Guy lived near Dingman and went to Nevada after the killing.
It was back in July of 2012 when Trinchero found her mother dead. Badly beaten with a cane, bound and sexually assaulted at her home on Downing Avenue in Stockton.
The violence left many, from neighbors to law enforcement ,angry and saddened. After so many years they didn't forget about Dingman, about finding answers. For that, her family is grateful.
"We also want to give our thanks to all those people who worked on this case to make this day happen for us," Trinchero said.
Jones did not say if Dingman and Guy knew each other.
Guy is expected to be in a Nevada courtroom on Monday. We should learn on that day when he will be extradited to California.