John Bacon

USA TODAY

A 13-year-old girl whose death led to the arrest of two Virginia Tech students was fatally stabbed the day she disappeared, a prosecutor said Tuesday.

Montgomery County, Va., prosecutor Mary Pettit also said an additional charge — accessory before the fact in the murder — was being filed against one of the suspects in the death of Nicole Lovell of Blacksburg, the Associated Press reported.

David Eisenhauer, 18, is charged with abduction and murder in Nicole's death. Natalie Keepers, 19, will face the latest charge, in addition to previous charges including illegally disposing of a body and accessory after the fact in the commission of a felony. Both will return to court late next month.

Blacksburg Police Lt. Mike Albert said this week that Eisenhauer, a freshman engineering student and member of the school's cross-country team, "used his relationship to his advantage to abduct ... and kill" Nicole. But Albert didn't discuss a motive. The investigation remains "very active," he said.

Albert said that Keepers, a sophomore engineering student, helped dispose of Nicole's body.

Nicole disappeared early Wednesday. Family members have said she apparently slipped out a bedroom window. Albert said Nicole and Eisenhauer were acquainted and apparently met online.

Nicole's body was found Saturday in rural North Carolina, almost 100 miles from her Blacksburg home.

Virginia Tech president Tim Sands posted a statement on the school's website, saying the school community was stunned and saddened by the case.

"Our hearts go out to Nicole’s family and friends," Sands said.