Hahn sworn in as L.A. mayor

Hahn speaks at Monday's ceremony

LOS ANGELES, California (CNN) -- Jogging up the steps to City Hall, an energetic James Hahn took the helm as Los Angeles' 40th mayor Monday morning, with his family by his side.

Hahn listened to words of advice from the community's religious leaders and watched as fellow city politicians were sworn in before he took the oath of the mayor's office at 10:36 a.m. (1:36 p.m. EDT).

Hahn's sister, Janice Hahn, was also sworn in Monday as a Los Angeles councilwoman.

Race hotly contested

Hahn, a Democrat, won a hotly contested race on June 6 against fellow Democrat Antonio Villaraigosa, a former state Assembly speaker.

Hahn, 50, was previously Los Angeles' city attorney for a record four terms.

He replaced outgoing Mayor Richard Riordan, a Republican, who was prohibited by law from running for a third term.

Hahn also made a plea to voters who cast their ballots for his opponent, Antonio Villaraigosa, a former state Assembly speaker.

"For those who did not support me, I will work every day to make sure you know that I am truly your mayor," he said. "I have always been committed to bringing the people of Los Angeles together because I am committed to keeping Los Angeles together."

Hahan stressing police reform

In his speech, Hahn stressed the importance of after-school programs for children, affordable housing and police reform.

"Police reform means we're going to have a police department that protects and respects the people it serves, " he said. "Police reform doesn't mean that we're going to scapegoat the 99 percent of our police men and women who do a great job for this city every single day."

Hahn -- who was previously Los Angeles' city attorney for a record four terms -- won 54 percent of the vote in the June 6 runoff race for mayor. Villaraigosa, a fellow Democrat, took 46 percent.