Oakland, California’s 148 homicides was a 57 percent increase over 2005 and the highest number in 11 years. The New York Times say law enforcement officials and community organizers are hard pressed to explain the rise, particularly because murders in nearby San Jose and San Francisco, have not increased much. Possible explanations include violent parolees returning from prison, increasing gang violence, the availability of guns, a growing methamphetamine trade, and police recruitment shortfalls.
Many criminologists question whether the increases in killings are large enough, widespread enough, or consistent enough to be considered a trend. “There are a thousand different stories competing against each other,” said Frank Zimring, a criminologist at the University of California, Berkeley. “When you put all the dots together, instead of knowing more, we know less.” Said Joel Wallman of the Harry Frank Guggenheim Foundation in New York City: “Two years does not a trend make, but two years can be the beginning of one; we just don't know yet. Some of these are such small changes, and the time frame of the trend is so short that it's very difficult to determine whether this is a real trend or just random noise.”