An attorney for the fiancee of a Yale University lab technician charged with killing a graduate student said Wednesday he's been told authorities are seeking a sample of her DNA.

Robert Berke, attorney for Jennifer Hramadka, told The Associated Press that it's unclear why authorities want her DNA. He says he was told in September after Annie Le was killed that she is not a suspect.

"I've been advised that they're seeking a sample of her DNA," Berke said.

Hramadka's boyfriend, Raymond Clark III, is charged with killing the 24-year-old Le five days before Le's planned wedding in September.

Berke said investigators wanted to interview Hramadka shortly after the crime, but the interview did not take place. He declined to comment on his reaction to the move.

A prosecutor and police declined to comment.

Clark and Hramadka were seen leaving a coffee shop in a car in which "blood-like stains" were found hours after Le was killed, according to search warrant affidavits unsealed Wednesday.

New Haven police said in September that they didn't expect to make more arrests in Le's killing.

Le's body was found stuffed behind a research lab wall in September on the day she was supposed to get married on Long Island. Autopsy results show Le was strangled, but the motive remains unclear.

Experts said investigators may seek someone's DNA to exclude him or her as a source of the DNA that was collected as evidence.

"It sounds like they have some DNA they don't know who it belongs to," said Dr. Bruce Goldberger, director of toxicology at the University of Florida. "They're trying to rule her in or rule her out as a contributor to that DNA."

Dr. John Howard, president of the National Association of Medical Examiners, cautioned against drawing conclusions about the move. He said investigators might want to address any claims or anticipated claims by the defense, such as that blood found was the suspect's fiancee's from a nosebleed.

Two days before Clark was arrested, investigators said they found blood "in plain view" on the kitchen floor near the entrance to his apartment, according to the search warrants. The warrants do not indicate the source of the blood found in Clark's apartment.

Authorities took plastic door panels and carpeting with "blood-like stains" from the Taurus in which Clark was riding in the hours after Le's disappearance.

Clark sent e-mails to Le "in the recent past," the affidavits said. Her e-mail address was found in a laboratory locker labeled "Ray," the documents said.

Clark has not yet entered a plea. His public defender, Joe Lopez, has said he intends to plead not guilty.