One possible explanation for the increase in crime is the state's recently created realignment program, that went into effect in October. As part of the realignment, people sent to state prisons are released into probation rather than parole as a means of easing overcrowded state prisons.
Property crime stood at its highest level since 2005, when the city reported 3,843 such crimes. Since 2005, property crimes have decreased annually, save for a 1% increase between 2007 and 2008.
Whether the changing patterns are indicative of a trend is hard to determine, experts said.
An uptick in murders, for example, doesn't necessarily indicate a change in overall safety, said UC Irvine criminologist John Hipp.
He pointed to the mass killing in Seal Beach, where eight murders in one day would show up in crime statistics as an anomaly not illustrative of the town's overall safety.
Recently, Hipp, along with 20 other researchers, produced a study on safety and economic trends in Southern California.
He said a reliably consistent indicator of an area's safety is the number of reported vehicles stolen because victims consistently report that particular crime at a rate of about 95% — a much higher rate than other crimes where victims choose not to come forward.
Last year, Costa Mesa drivers reported 282 stolen vehicles — the same as in 2010, crime data show. In reviewing the number of stolen vehicles since 2004 the Unified Crime Reports show that the recent high was 555 stolen cars in 2005.
Also, a drop in crime may not necessarily mean a city is safer but could mean that people feel less comfortable reporting crime, Hipp said, adding he could not speak specifically to Costa Mesa.
The FBI on its website cautions against using crime statistics as comparisons among cities, because crime "is a sociological phenomenon influenced by a variety of factors."
The Unified Crime Reports are compiled from data the FBI collects from cities across the country with populations greater than 100,000.
Because Newport Beach and Irvine have less than 100,000 residents, it is not included in the report.