(Video: Rich Marosi/Robert J. Lopez) I spent 22 years at the Los Angeles Times, where I worked on investigative and multimedia projects across the United States and in Mexico and Central America. I had a wonderful career and was part of a team of reporters that won the 2011 Pulitzer Prize for Public Service for exposing government corruption in Bell, a small city southeast of Los Angeles. But I was offered a great job and realized that it was time to take on a new and exciting challenge.

I was headed to the newsroom when the story broke: Fugitive former police officer Christopher Dorner had been in a shootout with law enforcement officers in the snow-covered mountains northeast of Los Angeles. INTERVIEW: I talk to Poynter Institute about Twitter and Dorner manhunt The ex-LAPD officer had been accused of killing three people, including a police officer. A second law enforcement officer would be mortally wounded in a raging gun battle that would soon erupt after Dorner fled the shootout and barricaded himself inside a mountainside cabin. It was a huge story that illustrated how social media has revolutionized the way we gather and share information.

iPhone video footage I shot during the final hours of Occupy L.A. The night began with Occupy L.A. protesters singing, dancing and chanting. But the festive mood changed as the LAPD swooped down on the City Hall encampment. In the end, nearly 300 people were arrested and the grassy park was...