Mayoral candidate Peter Carlisle has posted new TV ads on his campaign website. One touts his record as a crime fighter as the city’s prosecuting attorney from 1996 until July, when he resigned to run for mayor.

In the “experience” ad, he claims, “we are the safest big city in the United States.”

Carlisle told Civil Beat the claim is based on the Congressional Quarterly crime rankings, which are determined by crime statistics from the FBI.

In the CQ Press City Crime Rankings 2009-2010, which lists the “safest” and most “dangerous” cities in the United States, Honolulu has the lowest crime rate ranking of all cities with a population of 500,000 or more.

Congressional Quarterly calculates these city rankings by looking at murder, rape, robbery, aggravated assault and property crimes.

“The methodology for determining the city and metro area comparison crime rate rankings involves a multistep process in which the reported crime per 100,000 population rate are compared to the national reported crime per 100,000 population rate and then indexed to create a summary score and ranking across six areas of reported violent and property crime,” according to the city crime ranking’s methodology article

But critics question the validity of the ranking system.

The U.S. Conference of Mayors has raised concernsabout the rankings. It says they’re “bogus” for a number of reasons, including that auto thefts are treated the same way as homicides. Another reason is geographical. Older cities tend not to have the middle-class lower crime areas that newer, more suburban cities have within their boundaries.

The FBI also put a disclaimer in the 2006 FBI Uniform Crime Report, warning against using the data for rankings. “Each year when Crime in the United States is published, many entities—news media, tourism agencies, and other groups with an interest in crime in our Nation—use reported figures to compile rankings of cities and counties. These rankings, however, are merely a quick choice made by the data user; they provide no insight into the many variables that mold the crime in a particular town, city, county, state, region, or other jurisdiction. Consequently, these rankings lead to simplistic and/or incomplete analyses that often create misleading perceptions adversely affecting cities and counties, along with their residents.”

Civil Beat analyzed the crime statistics provided by the 2009 FBI Uniform Crime Report by charting the 10 cities with the lowest crime rates, according to CQ. Honolulu had the lowest rate of violent crime when dividing violent crime by population size.

Comparison of 10 Cities CQ Says Have Lowest Crime Rates in 2009-2010

Civil Beat Comparison of Those 10 Cities by Violent Crime per 100,000 People

Civil Beat found that the rankings change when violent crime is the measure, but Honolulu remains on top.

So even without relying on CQ’s rating, it’s clear that Carlisle isn’t out of line in boasting about the safety of Honolulu.