In 1958, the ninth-floor penthouse apartment was added, serving as the home of Walter R. Bimson, the chairman of the successful Valley National Bank of Arizona.

[2] In 2001, Maricopa County acquired the property, and historical renovations began in 2005 to restore the building.

The Security Building currently houses county offices; the Arizona State University Phoenix Urban Research Laboratory occupied the former penthouse until May 2012.

The Security Building is an example of Second Renaissance Revival architecture, using copper and hand-molded bricks.

The structure uses reinforced concrete, while the interior includes marble floors and walls, as well as brass elevator doors.