Investigators said they cannot forget the face or the case.
Amber Barker would have turned 27 this year.
She disappeared in 1997 while riding her bicycle home in her Northwest Oklahoma City neighborhood.
Police confirmed they have been quietly looking into this case for the past four years.
Investigators with their Crimes Against Children unit have been going over every piece of evidence with a fresh set of eyes to see if there was something that was missed the first time.
In court documents, there were three names mentioned of men police have interviewed.
Daniel Smith, Forest Rice, and Joseph Bishop were the men interviewed.
News 9 talked to Bishop Friday by phone.
“The whole family was questioned,” explained Bishop, who said he now lives in Dallas. “Everyone was questioned, taken down to the police station, and polygraphed and all that.”
Bishop said he does not know what happened to Amber Barker that day.
“No I have no idea,” said Bishop.
Bishop was dating Amber Barker's older sister Brandi at the time and admitted they had a rocky relationship.
He said what happened to Amber most likely was taken to the grave with Daniel Smith.
Smith was Amber's brother-in-law and committed suicide, just days after police questioned him about her disappearance.
"I was 19 at the time. I still have nightmares” said Bishop. “Then they let him go and three days later they found him hanging dead in the park.”
Bishop said he, like Amber's family, wants to know what happened. He said it is possible someone still knows something, but just hasn't come forward.
“I hope someday they get all the answers they are looking for,” said Bishop.
Police recovered Amber's bicycle, as well as her shoes and a sweater.
And on that sweater, police found partial DNA of a man, but have yet to make a match.
"Investigators believe that someone knows the whole story, or at least enough of the story to put the pieces together,” said MSgt. Gary Knight with the Oklahoma City Police Department. “And after all these years, we still want to hear from that person. That information is still vital to the case."
Oklahoma City police filed a search warrant on Thursday, requesting DNA from an Oklahoma County inmate.
He was identified as Forest Rice, but also goes by the name Steven Henley.
Police said he is not a suspect, but investigators believe he may have crucial information about Barker's disappearance that could lead them to the answer of what happened to Amber.
They said they also want to talk to Joseph Bishop for the very same reason.
“That's what we're there to do; to try to find out who's responsible for this kind of crime, hold them accountable, yet also locate the body and at least possibly give the family some closure to be able to bury their child,” said Knight.
Investigators said Amber Barker's mother passed away just last year.
And one of her sister's was found dead in 2013.
But there are still friends and family out there who want to see this case solved.
If you have any information you are urged to call Crime Stoppers at (405) 235-7300.
Authorities said there is a reward.