Kids play on the street at night in Irvine, Calif. Flickr/Mike Irvine, Calif. has the lowest violent crime rate among American cities with more than 100,000 people for the 9th year in a row.

The city of 223,000 residents reported 110 violent crimes to the FBI last year, making 2012 its safest year on record.

By comparison, Flint, Michigan, America's most dangerous city and half the size of Irvine, had 2,774 violent crimes in 2012. The FBI defines violent crime as murder, forcible rape, robbery, and aggravated assault.

Crime experts attribute Irvine's consistently low violent crime rate to its wealth and its demographics.

"It's basically a very affluent place with little poverty and a highly educated, often highly skilled population, many of them professionals," Elliott Currie, a criminology professor at University California-Irvine, told BI. "This isn't the population that's typically at high risk of getting involved in violent crime — quite the opposite."

The median income household income in Irvine is $85,615, which is $30,000 more than the national average. The city says 96% of its residents have a high school diploma and 66% are college graduates.

Irvine's heavily white (45%) and Asian (39%) population is also a driving force behind its low violent crime rate, says Jorja Leap, a social welfare professor at the University of California, Los Angeles.

"While Irvine is heavily Anglo, it is also heavily Asian. These are groups that historically 'get along' and share the same values, admire each other, and co-exist peaceably," Leap said.

The general public appears to share Leap's perception that whites and Asians make good neighbors. A recent Gallup survey of 4,300 adults found 87% described relations between Asians and whites as "good" (compared to 60% for whites and blacks).

Other cities with high populations of Asians and whits also scored well in the FBI's report. Fremont, CA (#2) is predominantly Asian (50%) and white (33%), and Plano, TX (#3) is heavily white (58%) and Asian (17%).

Irvine's design might also play into the low crime rate. The city is divided into a number of planned residential villages, some featuring schools and resort-style recreation like pools within the village boundaries.

"Irvine is a planned community and all properties built there, from its creation, have had an kind of economic selectivity," Leap told BI. "Each village has its own 'Covenants, Codes and Restrictions' which is an informal socioeconomic gatekeeper. People must have money and cherish order to buy and live here."