A reporter for The Washington Post since 1984, she has covered crime, homeland security, federal law enforcement, education, social services, and the U.S. Department of Justice.

Horwitz and fellow Post colleague Scott Higham shared the 2002 Pulitzer Prize for Investigative Reporting for their examination of the deaths of children in the D.C. foster care system.

The non-fiction book, released in May 2010, chronicles the 2001 disappearance of Washington, DC intern Chandra Levy, whose remains were found one year later in an isolated area of the city's 2,800-acre (11 km2) Rock Creek Park.

[1] In 2011, Horwitz was temporarily suspended by The Washington Post for plagiarism after she copied parts of an article about Jared Loughner.

[2] A native of Tucson, Arizona, Horwitz graduated from Bryn Mawr College and holds a master's degree in politics, philosophy and economy from Oxford University.