Crime is up across the board in the nation's second-largest city.

Statistics released Wednesday by the Los Angeles Police Department show that homicides and rapes are each up 9 percent and that robberies are up 13 percent. Violent crime overall increased by 20 percent.

At a news conference about the increases, Mayor Eric Garcetti and police Chief Charlie Beck emphasized the big picture. Viewed in greater historical context, the department says crime levels are still among the lowest Los Angeles has seen in the past 50 years and still far below where they were in the 1990s and early 2000s.

For instance, overall violent crime in 2015 was down by 23 percent compared with 2005.

A number of factors are driving this year's uptick, including a spike in gang violence.