GRAND FORKS (AP) - Twenty years after Annie Marie Korynta was stabbed repeatedly in her apartment, authorities are still looking for the killer.

Investigators say there are no new clues and no new evidence, but with advancements in technology they hope to learn more from evidence collected at the scene of the crime on May 11, 1987.

"There was a lot of evidence gathered that we still have," said Police Lt. Rahn Farder. "Since then, there have been tremendous strides with what DNA analysis can do. Almost certainly, you would expect the suspect's DNA can be found."

Farder said authorities believe that the killing was a "crime of passion," and that Korynta, 19, knew the attacker. The number of stab wounds would indicate "a lot of extreme emotion," Farder said.

"We're not looking at a robbery; we're not looking at a premeditated sexual assault," said Police Detective Mike Sholes, who is in charge of the investigation.

"Historically speaking, crimes of rage are from somebody you know," he said.

Authorities said there were no signs of forced entry to Korynta's apartment. Her niece, Kari Korynta, who shared the basement apartment with her aunt, discovered the body.

Police early on identified a "person of interest" but were not able to connect that person to the crime.

The apartment along the Red River was destroyed in the 1997 flood, but evidence collected two decades ago has been sent to the state crime lab in Bismarck. It could take months for any results, Farder said.