Vitter and Troubled Aide Brent Furer

Brent Furer, a longtime aide to Louisiana Sen. David Vitter, pleaded guilty in 2008 to charges stemming from a knife-wielding altercation with an ex- girlfriend. Brent Furer, who has been assigned by the senator to oversee women's issues, has had repeated brushes with the law dating back to the 1990s, an ABC News investigation has found. He is seen here in Washington, D.C. (ABC News)