The weapon used to kill a Virginia Tech police officer also was used to shoot a second man found dead on campus, Virginia State Police said on Friday.

Police said ballistics testing officially linked the two shootings, which prompted a lockdown of the campus on Thursday and revived memories of a gunman's 2007 rampage that left 33 people dead in one of the worst shooting incidents in U.S. history.

Police have not said whether the second unidentified man is the person who shot and killed Virginia Tech police officer Deriek W. Crouse, 39, during a traffic stop on Thursday. But they said a handgun was found near the second man's body, which was discovered about a half a mile/0.8 km away from the first shooting, appearing to support media accounts that the man shot himself as police approached.

Virginia Tech lifted the lockdown Thursday afternoon and said students could resume normal activities.

Shortly after noon/1:00 p.m. BT on Thursday, Crouse had a vehicle stopped in a campus parking lot when he was approached by an unknown man and fatally shot, police said. The man then fled.

About 30 minutes later a Montgomery County sheriff's deputy saw a man in a nearby parking lot. When the deputy reached the man, he found him dead on the ground with a handgun nearby. Police said they were still awaiting confirmation of the man's identity.

Police later recovered a discarded backpack on campus with clothing inside that was similar to that worn by the man seen in video taken by Crouse's patrol car.

Crouse joined the Virginia Tech police department in October 2007 and is survived by his wife, five children and step-children, and his mother and brother.

The incident evoked grim memories of April 2007 when a mentally deranged student killed 32 people and wounded 25 before committing suicide on campus about 250 miles/400 km southwest of Washington. It was the deadliest attack by a single gunman in U.S. history.

A candlelight vigil has been planned for Friday night near the memorial for the victims of the 2007 shooting.

(Editing by Bill Trott)