Law enforcement officials are still not sure how the body of 17-year-old Carolyn Lee Andrew ended up in a shallow grave in Duluth's Twin Ponds in 1981. But thanks to DNA technology, nearly 34 years later, authorities believe they've finally determined the identity of her killer, reports the Duluth News Tribune.

Crediting advances in DNA technology, local and state officials said Monday that they've tied the homicide to Cecil Wayne Oliver, who died in 1988. The finding was announced at a news conference by Minnesota Bureau of Criminal Apprehension and Duluth Police Department officials.

The officials said a DNA sample taken recently from Oliver's remains was a positive match for DNA recovered from Andrew's body in 1981.

Using new technology in March 2014, investigators found a partial match between the DNA sample and an offender in the system. Testing indicated that the man who provided the sample was closely related to the man whose DNA was found on Andrew's body.

It turned out that offender in the DNA database was Cecil Oliver's son.

Investigators acknowledged that unanswered questions will linger. But with the announcement of the suspected killer, they have officially closed the case.