Brenda Allen (born Marie Mitchell) was a madam based in Los Angeles, California, whose arrest in 1948 triggered a scandal that led to the reform of the Los Angeles Police Department (L.A.P.D.). Allen received police protection due to her relationship with Sergeant Elmer V. Jackson of the L.A.P.D.'s administrative vice squad, who reportedly was her lover.
Allen began work as a prostitute in Los Angeles in the 1930s, though she already had several prior morals charges in other US cities. She rose to prominence around 1940 as the successor to Ann Forrester (aka "Black Widow"), who had previously run a $5,000-a-week prostitution syndicate but was convicted and handed a prison sentence.
After an attempted robbery of Brenda Allen and Sergeant Jackson in which Jackson shot and killed the perpetrator, the press and other members of the police became aware of their relationship. Wiretaps led to the arrest of Allen and the resulting publicity to the convening of a grand jury.
The publicity from the grand jury revelations of police corruption led to the resignation of L.A.P.D. Chief Clemence B. Horrall and his replacement by retired Marine Major General William A. Worton, who had served with the Marine Corps' III Amphibious Corps at the Battle of Okinawa.
Worton was appointed by L.A. mayor Fletcher Bowron on a temporary basis. He served from July 1949 to August 1950, when he was replaced as chief by William H. Parker, who had served the General as a special aide and then as head of Internal Affairs. (Horrall's deputy chief, Joe Reed, also resigned after being shamed by grand jury testimony.) It was Parker, in his 16-year reign as Police Chief, who is credited with cleaning up the L.A.P.D.
The story of Brenda Allen plays a role in the 2011 video game L.A. Noire.