[4] He represented clients in diverse practice areas such as real estate, entertainment, corporate transactions, securities, banking, bankruptcy, and employment.

During his ten years as a federal prosecutor, Justice Johnson received numerous awards and commendations for his work on behalf of the United States.

[6] That award honored his wiretap investigation and prosecution of a nationwide crack cocaine and money-laundering network controlled by a notorious Los Angeles-based gang.

[5] In his tenure at the U.S. Attorney's Office, Justice Johnson was recognized nationally as an expert on the use and defense of court-authorized wiretaps in the course of federal criminal investigations and prosecutions.

[4] He is a member of the Court Facilities Advisory Committee ("CFAC"),[10] appointed by Chief Justice Cantil-Sakauye in July 2011 to advise the Judicial Council of California on prioritization of courthouse construction projects throughout the state.

[1][15] He is a director of the Western Justice Center Foundation, which works to educate citizens of all ages about, and to facilitate, nonviolent dispute resolution.

[1] On January 14, 2019, Johnson was accused of sexual misconduct against several women, including fellow Court of Appeal justices Victoria Gerrard Chaney and Elizabeth A. Grimes, over a fifteen-year period.

[20] On June 2, 2020, the Commission on Judicial Performance ordered his removal from the bench, a decision appealable at that time to the California Supreme Court.

[21] On January 28, 2021, the California Supreme Court rejected hearing his appeal—effectively upholding the commission's decision to remove Justice Johnson from the bench.