A man accused of raping and murdering a 13-year-old girl in 1982 has been found guilty by a California jury after DNA from his cigarette linked him to the decades-old cold case, according to prosecutors. James Oliver Unick, of Willows, was convicted of murder on Friday, February 13, with the special circumstance "related to the sexual assault during the commission of the murder" in connection with the death of Sarah Geer, the Sonoma County District Attorney's Office said in a news release issued that day. The jury's verdict came after Unick previously pleaded not guilty, court records show. "This guilty verdict is a testament to everyone who never gave up searching for Sarah's killer," Sonoma County District Attorney Carla Rodriguez said in a statement. "This is the coldest case ever presented to a Sonoma County jury." "While 44 years is too long to wait, justice has finally been served, both to Sarah's loved ones as well as her community," Rodriguez added. Man Arrested in 1997 Murder of Woman Killed at California Home: Police Unick's defense attorney did not immediately return Us Weekly's request for comment on Tuesday, February 17. Unick is accused of killing Sarah the evening of May 23, 1982, after she left a friend's home in Cloverdale, according to prosecutors. While Sarah was walking downtown, Unick attacked her "near an alley off a residential street" and dragged her down the alley, the district attorney's office said. Unick dragged her further to a "secluded area" next to an apartment building that was behind a fence, where he "brutally raped Sarah and strangled her to death using her own shorts as a ligature," according to the district attorney's office. The next morning, a firefighter came across Sarah's body while he was heading home from a shift, prosecutors said. Due to limits in forensic science, the case remained cold for multiple decades, according to the district attorney's office. In 2003, the first break in the case came when a California Department of Justice criminalist developed a DNA profile of a suspect after analyzing sperm found on Sarah's underwear, prosecutors said. However, the DNA profile was not linked to a potential suspect until years later, according to the district attorney's office. After the Cloverdale police department hired private investigator Kevin Cline to help in 2021, the FBI also got involved to try and identify the DNA profile, prosecutors said. Ultimately, the DNA profile was discovered to match four people: Unick and three of his brothers, according to the district attorney's office. Unick was narrowed down as the suspect after FBI agents obtained a cigarette that Unick had smoked and discarded, according to prosecutors. "A DNA analysis of the cigarette butt confirmed that Unick's DNA matched the 2003 profile, and his DNA additionally matched DNA collected on numerous articles of clothing that Sarah had been wearing at the time of her death," the district attorney's office said. Woman's Body Found in Ditch in 1996. Now, Man Charged in Cold Case Murder Unick was arrested at his home in Willows in July 2024 in connection with Sarah's death, according to prosecutors. During Unick's jury trial, which lasted for a month, he accused Sarah of propositioning him for sex while he was at a Cloverdale arcade and said "they had consensual sex on a hillside," the district attorney's office said. He implied Sarah "must have been assaulted and murdered later that evening by a phantom man who failed to leave behind any DNA evidence," according to the office. The jury, however, did not buy Unick's story, the district attorney's office said. Unick is expected to be sentenced to life in prison without the possibility of parole, according to prosecutors.