Virginia Tech officials have lifted the campus lockdown and said they have recovered a weapon following the shooting death of a police officer and an unidentified man on Thursday.

The police officer was shot to death at a traffic stop at the Cassell Coliseum parking lot on Spring Road. He was a four-year veteran of the Virginia Tech Police and was assigned to the patrol division, Virginia State Police said.

Witnesses said the suspect in the shooting fled the scene toward another crime scene some quarter mile away, according to the school's Web site.

A man's body was found at that scene with a gunshot wound.

The names of the victims haven't been released and officials haven't confirmed whether the unidentified male found dead in a parking lot is the gunman.

Police have said they recovered a weapon from the crime scene but didn't say what kind of weapon it was.

The campus alert was lifted after 4 p.m. when police determined there was no longer an active threat on campus.

Police have said that the investigation will take weeks and they haven't yet established a motive for the killings.

University officials have said they don't believe the shooter was the person involved in the traffic stop.

Thursday's double murder was a grim reminder of a 2007 shooting on campus that left 32 people dead.

Reports are that the shooting happened the same day Tech's police chief and other university officials were in Washington, D.C. appealing a $55,000 fine for violating the federal Clery Act during the 2007 shootings.

Virginia Tech was cited by the U.S. Department of Education for not sending a timely warning during the 2007 mass shootings.