When the state began shifting hundreds of convicted criminals to county responsibility in 2011, the change provoked fear and debate in communities across California over whether crime rates would spike.

Yet two years in, the image of hardened prisoners flooding local streets and committing more crimes has not been borne out, several Sonoma County law enforcement leaders said.

While crime has increased slightly in some communities, the changes remain slight — and crime has even declined in other communities.

"In unincorporated areas, crime is down," Sonoma County Sheriff Steve Freitas said. "I don't think we can say realignment is responsible for it being down."

Santa Rosa Police Chief Tom Schwedhelm said the trend holds true for Santa Rosa. Property crimes dropped 11 percent in the first seven months of 2013, compared to the same period a year ago.

Nationwide, crime rates have been on a historic downward trend for two decades.

Yet there's evidence in California indicating crime may be creeping up again or at least hitting a plateau, said Magnus Lofstrom, a research fellow with Public Policy Institute of California.

Lofstrom and a colleague with the University of California's Graduate School of Public Policy have just begun delving into an analysis of crime trends in the state. They are studying how crime rates have changed during the first two years of the Public Safety Realignment Plan, which funneled thousands of convicted felons previously handled by the state prison system into county jails and probation offices. They hope to publish their findings by the end of the year.

"It might be picking up ever so slightly," said Lofstrom. "There are some reversals in the long-term trends."

That appears true in Petaluma. In the first six months of 2013, serious crimes were up 11 percent compared to the same period last year, pushed mostly by an uptick in property crimes such as burglary, Petaluma Police Chief Pat Williams said.

"Overall our crime is still pretty good, but property crimes are a big, big issue, and that's in the wheelhouse of these folks," Williams said.

Aggravated assault nearly doubled in Cotati, from 27 in 2011 to 47 in 2012. Jail bookings increased "significantly," Cotati Police Chief Michael Parish said.

"But can I blame it on realignment? I don't know," Parish said.

Parish, the other chiefs and the sheriff all said it's too early to attribute fluctuations in crime rates to realignment.

"If it's an unsolved burglary, how do I know the burglar is a realignment offender? I'm not sure statistically how you equate cause and effect," Schwedhelm said. "It's too early to say there's a trend one way or the other."