The incident happened near Pico Boulevard and Bonnie Brae Street in the Pico-Union District around 9 p.m.
Police say a man armed with a gun approached plainclothes officers. An officer-involved shooting occurred, and the suspect was declared dead at the scene. He was identified as 37-year-old Juan Diaz Chavez.
At least one other suspect escaped, forcing police to search and question many of the people inside the church. They brought some of the churchgoers out with their hands up or zip-tied. That suspect remains at large Wednesday.No officers were injured in the incident. The shooting will be investigated by the Los Angeles County District Attorney's Office as well as the County Office of Independent Review, which is standard in officer-involved shooting cases.
City News Service contributed to this report.