An unidentified teenage girl who was found fatally shot in upstate New York in 1979 has finally been revealed to be Tammy Jo Alexander, thanks to recent DNA testing, the Livingston County Sheriff’s Office confirms to PEOPLE.
Alexander, who would now be 51, was known as “Jane Doe 1979” until last week.
In the summer of 2014, a high school friend of Alexander’s decided to contact her half-sister, expressing her concern that she was never found.
“Her half-sister had always assumed that their mother had filed a missing person’s report,” Sheriff Thomas Dougherty tells PEOPLE. “But she never did. This poor girl went missing 35 years ago and no one looked for her.”
Meanwhile, for those 35 years, police in New York tried to solve the case of an unidentified young woman who had been murdered.
Alexander was found on a rainy night in Caledonia, New York, in November 1979 and had a gunshot wound from a .38-caliber handgun above her right eye.
She apparently had been dragged and shot again, in the back.
“This case became the largest criminal investigation in county history,” Dougherty says. “Everyone in this town has always been very invested in finding out who she was and what happened to her.”
Although her body was found in New York, police suspected the victim had come from a place with a warmer climate.
“We assumed she was from somewhere warm because when we found her, she had a suntan,” he said of Alexander, who was from Brooksville, Florida. “But now that we know who she is, we not only know more about her, but it can help us find her killer.”
Dougherty himself has been invested in this case for a long time.
“It feels so good to know her name is Tammy,” he says. “And to know now that we are closer to finding out who did such an awful thing to this young girl.”
The Livingston County Sheriff’s Office continues to lead the investigation while working closely with the Hernando County Florida Sheriff’s Office and the FBI. Authorities are asking anyone with information about the case to call 1-800-CALLFBI (225-5324).