(AP) - A gunman killed a police officer in a Virginia Tech parking lot Thursday and was found dead nearby in a baffling attack that sent shudders through the campus nearly five years after it was the scene of the deadliest shooting rampage in modern U.S. history.

The shooting took place on the same day Virginia Tech officials were in Washington, fighting a government fine over their alleged mishandling of the 2007 bloodbath.

Before it became clear that the gunman in Thursday's attack was dead, the school applied the lessons learned during the last tragedy, locking down the campus and using a high-tech alert system to warn students and faculty members to stay indoors.

Officer Deriek W. Crouse, a 39-year-old Army veteran and father of five, was killed after pulling a driver over in a traffic stop. The gunman - who was not involved in the traffic stop - walked into the parking lot and shot the officer, Sgt. Robert Carpentieri said. Police wouldn't talk about a motive.

A law enforcement official who spoke on the condition of anonymity confirmed the gunman was dead, but wouldn't say how.

It appeared the gunman died about a quarter-mile away from the traffic stop, in another school parking lot, where officials said a man was found dead with a gun nearby. While police at a news conference wouldn't confirm the second body was the gunman, Carpentieri said "you can kind of read between the lines."

The shooting prompted a lockdown that lasted for about four hours.

"Today, tragedy again struck Virginia Tech," said university president Charles Steger. "Our hearts are broken again."

Crouse joined the Virginia Tech Police Department in 2007, just six months after 33 people were killed at the school in the deadliest mass shooting in modern U.S. history. He also worked at a jail and a sheriff's department. State police were still investigating whether he had been specifically targeted.

Sudents were preparing for exams were suddenly told to hunker down. Heavily armed officers walked around campus as caravans of SWAT vehicles and other police cars with emergency lights flashing patrolled nearby.

"A lot of people, especially toward the beginning were scared," said Jared Brumfield, a 19-year-old freshman from Culpeper, Va., who was locked in the Squires Student Center since around 1:30 p.m.

The university sent updates about every 30 minutes, regardless of whether they had any new information, school spokesman Mark Owczarski said.