Jill Leovy asks the question in her Homicide Report blog at LATimes.com: "Are Black-vs.-Brown Racial Tensions Driving Homicide in L.A.?" Her answer is no.

Take the four most violent Los Angeles police precincts--Newton, 77th Street, Southwest and Southeast.

These racially mixed divisions cover South-Central Los Angeles and surrounding areas and consistently rank highest in homicides among the 19 LAPD precincts. Last year they accounted for nearly half of all the murders in the city.

But out of a total of 236 homicides in these four divisions last year, just 22 involved Latinos killing blacks, or blacks killing Latinos.

The vast majority--nearly 90%--involved suspects and victims of the same race. In a few other cases, the suspects are unknown, and could represent disparate races. But even in those--a mix of stray-bullet, gang- and narcotic-related killings--race is not believed to be a motive.

In areas patrolled by the L.A. County Sheriff's Department, too, the pattern of killings on the street is “almost the opposite” of the picture lately highlighted in the media, sheriff's Cmdr. Pete Amico says.

The tilt is so far the other way that some homicide investigators say what actually perplexes them is how little racial crossover there is in killings.

Last week she asked if there are fewer homicides on rainy days. Answer.