(KRON) -- A man was found guilty Thursday of the 1982 murder of 14-year-old De Anna Lynn Johnson, the Solano County District Attorney’s Office announced. Marvin Ray Markle, now 59 years old, was considered a suspect early in the investigation before the case went cold for more than 30 years. Mark le was arrested on Jan. 24, 2017, for the murder of Johnson. At the time, he was serving a life sentence for the 2001 murder of 41-year-old Shirley Ann Pratt. On Nov. 15, 1982, the Vacaville Police Department said Johnson attended a house party where Markle, who was 17 years old at the time, was believed to be among the guests. The next day, a Southern Pacific Railroad employee found Johnson’s body on the train tracks near her home. She had been strangled and her body badly bludgeoned. De Anna Lynn Johnson (Solano County District Attorney's Office) “Chief Deputy District Attorney Paul Sequeira, who personally handled the case, was able to overcome many obstacles that are inherent in unsolved murder cases,” the DA’s office said. “Fortunately, Retired Vacaville Police Officers Joseph Munoz (88) and Don Waller, who originally investigated De Anna Lynn Johnson’s murder in 1982, were still around the area and available to testify at the trial.” Man arrested in 2009 rape cold case in Sunnyvale On Thursday, after three weeks of trial, the jury found Markle guilty of first-degree murder. Jurors also found the enhancement allegation of use of a deadly weapon true. “Today, the individual responsible for her tragic death in Vacaville was convicted, hopefully bringing a sense of closure to her family and our community,” the Vacaville Police Department said Thursday. “Our thoughts remain with her loved ones as they continue to navigate this difficult time.” ...read more read less