Mack first moved to
Oxnard, California, and he worked at the
Camarillo State Mental Hospital As a president and member of the organization he fought against school segregation and advocated for African American worker rights. At the time, Mack and Mayor
Tom Bradley were criticized by young activists for being too removed from the real life experiences of everyday
African Americans; Mack rejected the criticism. Over the next few years, he helped rebuild the area by "renovat[ing] 63% of damaged businesses, created jobs," and especially rebuilt the
Crenshaw Boulevard corridor. He became an advocate for neighborliness between blacks and Hispanics in the area. In 1995, however, after
O. J. Simpson was tried and acquitted for the
murders of his ex-wife
Nicole Brown Simpson and her friend
Ron Goldman despite circumstantial and physical evidence pointing to Simpson's guilt, Mack expressed his support for Simpson, and congratulated the predominantly-black jury for acquitting Simpson as a way of creating a "level racial playing field" in the country, leading to harsh criticism. Mack was the president of the board of police commissioners of the
Los Angeles Police Department from 2005 to 2007, and as a member through 2013. Under his leadership, the commission became the "driving force" behind several LAPD improvements, including video cameras in squad cars to increase accountability among patrol officers, and the department achieving full compliance with the federal consent decree that had been in place since 2001. He subsequently served on the Los Angeles City Planning Commission. In 2018, Mack supported the nomination of
Michel Moore as the new
Chief of the Los Angeles Police Department. In particular, he stressed Moore's expertise in
community policing and his dedication to "eradicat[ing] racism and brutality within the LAPD." ==Personal life, death, and legacy==