Brown went on to earn a master's degree in sociology from San José State University in 1964, and became an assistant professor there in 1968. At the University of California, Berkeley, he earned a second master's in criminology in 1968, and became chairman and professor of the Department of Administration of Justice at Portland State University in the same year. He earned a doctorate in criminology from Berkeley in 1970.
Brown was the first African American to be appointed Police Chief to the City of Houston, and served from 1982-1990. He was first appointed by Mayor Kathy Whitmire. There he implemented methods of Community Policing.
Brown next took his leadership to New York City as Police Commissioner where he implemented community policing citywide. After one year, crime went down in every category. That was the start of the most drastic reduction of crime in the history of that City. Brown is known through the law enforcement community as the Father of Community Policing.
In 1993 Brown moved to Washington, DC for a national appointment as the Director of the Office of National Drug Control Policy (or "Drug Czar") under President Bill Clinton. The Senate unanimously confirmed his appointment.
In 1997, Brown was the first African American to be elected mayor in the City of Houston. Brown presided over what many say was the most prosperous six-year period in the history of Houston. Under his leadership, the city invested in extensive infrastructure: it started its first light-rail system and obtained voter approval for its extension, along with increases in bus service, park and ride, and HOV lanes; opened three new state-of-the-art professional sports facilities; revitalized the downtown area; constructed the City's first convention center hotel, and doubled the size of the convention center; and constructed the Hobby Center of the Performing Arts. In addition, it built and renovated new libraries, police and fire stations; undertook a $2.9 billion development program at the City's airport system that consisted of new terminals and runways; a consolidated car rental facility; in addition to renovating other terminals and runways; and built a new water treatment plant.
Brown also advanced the City's affirmative action program; installed programs in City libraries to provide access to the Internet; built the state-of-the-art Houston Emergency Communications Center; implemented e-government, and opened new parks. Many of the projects were planned or started by previous mayor Bob Lanier, who served until term limits. Brown led trade missions for the business community to other countries and promoted international trade. He increased the number of foreign consulates.
Brown is a member of Alpha Phi Alpha, the first intercollegiate Greek-letter fraternity established by African Americans. He is also a member of Sigma Pi Phi, an African-American fraternity for those who have achieved distinction in their chosen profession.
Brown is a co-founder of the National Organization of Black Law Enforcement Executives (NOBLE). Brown is chairman and CEO of Brown Group International, which develops solutions to complex problems in public safety, home land security, crisis management, government relations, international trade, and other concerns.
Brown undertook a massive program to reconstruct the downtown street system and replace the aging underground utility system. The heavy roadway reconstruction in Houston's downtown area and accompanying traffic problems was made a campaign issue by his opponent. In 2001 Brown narrowly survived a reelection challenge and runoff against city councilman Orlando Sanchez, who campaigned against Brown's handling of Houston roadways. Sanchez' supporters made issue of poor street conditions, campaigning that the "P stands for Pothole," referencing Brown's middle initial. Sanchez himself used a Hummer adorned with the banner "With Brown in Town it's the only way to get around" as his campaign vehicle.
Sanchez used the media publicity where a Houston firefighter's death in the line of duty resulted in endorsements from the fire/emergency medical services sector. Brown was endorsed by the Houston Police Officers' Association.
The Brown-Sanchez election produced heated rhetoric and involvement from several national political figures. Brown received the endorsement of former president Bill Clinton while Sanchez was endorsed by president George W. Bush, former president and Mrs Bush, Rudy Giuliani and a host of other republicans. Some members of the President's cabinet campaigned for Sanchez in Houston. The contest also produced racial undertones as Sanchez, a Cuban American vying to become the first Hispanic mayor of Houston, challenged Brown, the city's first African American mayor. Brown's campaign drafted family members of murder victim James Byrd Jr. for taped political ads accusing Sanchez of racial insensitivity towards Blacks for failing to support a hate crimes law. Sanchez, in turn, accused Brown of playing the race card against Hispanic voters.
Voting split heavily on racial lines with a majority of Hispanic and Anglo voters supporting Sanchez and a majority of African Americans and Asians supporting Brown. Brown narrowly won reelection by a margin of three percentage point following heavy voter turnout in predominantly Black precincts, compared to relatively light turnout in Hispanic precincts.
Brown's 2001 reelection was one of the last major political campaigns supported by the Houston-based Enron Corporation, which collapsed in a financial scandal only days after Brown's reelection.