Nelson now lives in Georgia and is being held in jail just outside of Atlanta. However, there are concerns about his health and whether he will live long enough for the case to go to trial.
Prosecutors from Greene and Clark counties held a joint news conference on Friday and said a special grand jury session was held on Wednesday. They said during that session, the grand jury returned a six-count indictment against Nelson, linking him to two unsolved homicides.
Authorities said one of the murders happened in Greene County and the other happened in Clark County.
Prosecutors said that if and when the case goes to trial, it will be held in Greene County. Greene County prosecutors said Nelson shot and killed 18-year-old Stephen Risner in 1978 at the Omega gas station on Route 68 in Xenia.
Investigators said Risner was working as a gas station attendant when he was gunned down. However, prosecutors said ballistic evidence has now linked Nelson to an unsolved homicide at a gas station in Springfield Township that also happened in 1978.
Homer Griffitts was gunned down while working at the Kayo Service Station on Yellow Springs Road and Leffle Lane, according to investigators. Griffitts died in front of his 10-year-old son.
Prosecutors said they have evidence that the same gun was used in both crimes.
Right now, Nelson is being held in the Cobb County Jail. However, his attorney said Nelson has advanced cancer and is only expected to live four to six months.
During the news conference, prosecutor Bill Schenke said that Nelson's health condition will not stop him from trying to take him to trial.