EMBED >More News Videos ABC13's Courtney Fischer learns more about the cold case investigation into the 1981 murder of Virginia Freeman.

EMBED >More News Videos DNA found under Freeman's fingernails was retested by Parabon Snapshot DNA and helped produce a picture of what the killer looked like.

EMBED >More News Videos In 1981, Virginia Freeman went to sell a house in College Station and was never seen alive again.

EMBED >More News Videos How phenotyping is being used in forensics.

BRYAN, Texas (KTRK) -- More than 36 years ago, a mother and successful realtor was stabbed and left to die behind a home in College Station.Virginia Freeman's killer was never caught.The Brazos County case went cold. But now, investigators have new hope. DNA found under Freeman's fingernails the day she was murdered, was resubmitted for testing. New technology produced a composite sketch of the man who murdered Freeman. For the first time, detectives have seen the face of her killer.December 1, 1981 was a day Brazos County Sheriff Chris Kirk will never forget.Freeman, a bubbly 40-year-old realtor, stopped at a ranch on Greens Prairie Road, in a rural part of College Station. Ginger, as her friends called her, was meeting a potential buyer. He had phoned Freeman's realty office around three that afternoon. Former colleagues say the caller had a "country sounding accent."He said he had $73,000 cash and wanted to buy property far from town."Was he somebody local? Who knows?" Susan Livingston asked.Livingston worked with Freeman at Real Estate Mart in Bryan. All the agents at the time were female."She was a very personable person. Very outgoing, smiley, loved life," Livingston said. "And loved being a mother. Loved being a wife."Less than an hour after that call came into the office, Freeman would be dead. Never again would she see her husband, son and daughter."What really struck me was how violent of an attack it was," Kirk said.Freeman was stabbed in the neck 11 times, strangled and bludgeoned in the head with a rock. She died fighting for her life, behind the home she was trying to sell.Kirk was a young deputy at the time. He was called to photograph the crime scene. Looking through the pictures more than three decades later, Kirk let out a heavy sigh.A detective unwrapped Freeman's loafers, still dusty with dirt, from a brown paper bag. It's one of the many items boxed as evidence in the basement of the Brazos County Sheriff's Office.Despite tracking more than five dozen leads, cross country, investigators never found Freeman's killer."It's hard that the answers are out there and we just can't put our fingers on it," Kirk said.But they won't give up.The killer's DNA was found on Freeman, collected from her fingernails. DNA testing wasn't prevalent in 1981, but the medical examiner at the time thought to clip Freeman's nails and save them. A few months ago, that DNA was re-analyzed by a company called Parabon Snapshot DNA Phenotyping.Phenotyping is a process that predicts what a person looks like by analyzing billions of particles of DNA. It produces a composite sketch based on six traits: Eye color, skin color, hair color, freckling, shape of face and ancestry."It was remarkable. To think we were looking at the face of a killer? That was certainly something that took us back," Kirk said."Investigators are coming to us because they need leads," said Dr. Ellen McRae Greytak with Parabon Snapshot. "We do lots of testing to ensure that it's extremely accurate.""It's encouraging," Livingston said. "I hope that sheds some new light."The release of this sketch did indeed breathe new life into Freeman's case. Investigators are chasing new leads. They've shown the composite sketch of Freeman's killer to several past witnesses."One day, we're going to find this killer," Kirk says.Freeman's son and daughter now live in Austin. Her husband has since passed away. While it's too painful for her children to talk about the case, her son says he's grateful investigators never lost interest in his mother's case.