A federal prosecutor says no charges will be filed against a security guard who shot and killed a man wielding a knife at Union Station in the District of Columbia.

U.S. Attorney's Office spokesman Bill Miller said Tuesday there's not enough evidence to pursue federal criminal civil rights or local charges against the guard, whose identity has not been released. In a news release, the office said its staff and the Metropolitan Police Department reviewed the Sept. 11, 2015, incident.

Police say officers saw 57-year-old William Thomas Wilson Jr. of southeast Washington stabbing a woman that afternoon at Union Station.

Prosecutors say Wilson raised a knife when officers tried to stop him from escaping. A security guard shot Wilson once.

Wilson died at a hospital. The wounded woman survived.