RIVERSIDE, Calif. (KABC) -- The Riverside County District Attorney's office is asking for the public's help in solving the identity of a woman murdered by the so-called "Happy Face" serial killer 31 years ago.
Keith Hunter Jesperson, 68, is behind the deaths of at least eight women. He was known as the "Happy Face Killer" for the smiley face drawings he made in a letter to a newspaper, in which he bragged about his crimes.
One of his victims has yet to be identified.
"It's important for us to give her back her identify as part of the seeking of justice," Riverside County District Attorney Mike Hestrin told Eyewitness News.
Investigators are the closest they've ever been to identifying the eighth victim thanks to advances in DNA technology, Hestrin said.
Jesperson was convicted of the unidentified woman's murder 14 years ago.
Renderings and sketches of the woman, who Jesperson says was named "Claudia," were released Monday.
She is described as a white woman, 25-35 years old, 5 feet 7 inches tall, with brown or dyed blonde hair and a tattoo of two small dots on her right thumb. When found, she was wearing a t-shirt with a motorcycle print.
Based on evidence gathered and the murderer's own confession, investigators say "Claudia" was hitchhiking along Interstate 15 in August 1992 from the Las Vegas or Barstow region to the Los Angeles area. She crossed paths with Jesperson and his purple Peterbilt south of Victorville at a brake stop.
Jesperson strangled her in his semi-trailer and drove to Blythe where he dumped her body.
Improvements in forensic science allowed investigators and genealogists to determine some relatives, including her biological but now deceased father of Cameron County, Texas, according to the DAs office. Several of the victim's half-siblings were also identified but they were not biological matches to her mother.
The victim's maternal side of the family is believed to have ties to the Louisiana and/or southeast Texas area, according to investigators.
Anyone with additional leads to the victim's identity was asked to call the Cold Case Hotline at 951-955-5567 or email firstname.lastname@example.org.
City News Service contributed to this report.