Investigators are trying to determine why a man shot and killed a Virginia Tech campus police officer Thursday before turning the gun on himself. NBC's Pete Williams reports.
The Virginia Tech police officer who was killed on campus during a traffic stop was identified as four-year member of the force who was married and had five children and stepchildren.
The Virginia Tech News website said Deriek W. Crouse, 39, of Christiansburg, was survived by his wife, five children and step-children, and his mother and brother. Funeral arrangements were pending.

AP
Police Officer Deriek Crouse
The site said Crouse joined the campus Police Department on Oct. 27, 2007, and served in the patrol division. He had been a member of the force's Emergency Response Team since February, and in 2008 he received an award for his commitment to the department's efforts against driving under the influence.
He was an Army veteran who had worked at the New River Valley Jail and the Montgomery County Sheriff's Department.
The gunman thought to have killed Crouse was found dead on campus with a gunshot wound.
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