Authorities say six months after a missing Noblesville woman's remains were found in north-central Indiana they're still not sure how she died.

Seventy-four-year-old Dorothy Heard was reported missing from her home in June 2011. Her remains were found in February near the Mississinewa River a few miles northwest of Marion.

The Grant County coroner's office used DNA to identify the remains as those of Heard.

But Coroner Stephen Dorsey tells the Kokomo Tribune (http://bit.ly/P2k1kp ) that his office could not determine a cause of death. He says he ruled Heard's cause of death undetermined "and the manner of death unknown."

Noblesville police spokesman Lt. Bruce Barnes says Heard's 47-year-old nephew, Donald L. Burns, is still considered a person of interest in the case.