There are many factors that can contribute to the crime rate in America--the econmony, geography and the weather all seem to play a role. Social scientists, politicians and law enforcement officials continually attempt to identify the factors that influence criminal activity in the hope that they can use the information to reduce crime.
High Population/Population Density
According to the FBI's report, "Crime in the United States," areas with high populations as well as those with dense populations often have a higher rate of crime. These crimes tend to be residential in nature: burglaries, car theft, larceny, and domestic assaults.
Areas with high commercial populations (business districts) usually have more crime. Offenses in these areas tend to be "business" crimes including commercial burglaries, forgery, larceny, and shoplifting. In addition, there are more crimes committed against people in these areas, such as muggings, theft of bikes, cars and personal objects in cars.
According to a 2002 study conducted by Bruce Weinburg at Ohio State University, a poor economy has an immense impact on crime rates. Weingburg and colleagues studied national crimes rates between 1979 and 1997 and found that the increase of crime during that period was most likely attributable to falling wages and increased unemployment among low-educated men. Weinburg believes that crime increases with declining wages because the payoff for criminal activity is greater. The study was published in The Review of Economics and Statistics.
It has been long theorized that warm weather tends to aggravate the occurrence of violent crimes. In 1984, support was found for this theory when John Rotton, a psychologist with Florida International University, conducted a study based on 858 U.S. cities. He found that hot, dry weather was a significant a factor in predicting crime as economic factors or population density. Rape, robbery and murder were all more likely to occur on warm days than on cold or rainy days. Although Dr. Rotton's study was conducted decades ago, the FBI's 2007 "Crime in the United States" report also targets climate as an important factor in crime rates.
Neighborhoods that are run-down, graffiti-covered, and generally in a state of disorder tend to have more crime than orderly neighborhoods. In 1982, social scientists George L. Kelling (of Rutgers University) and James Q. Wilson (of Harvard University), came up with a hypothesis to explain this phenomena: the "broken windows" theory. According to this theory, when one broken window of a building remains broken, eventually all other windows of the building will become broken. The first broken window signals to the citizenry that no one cares about it, nor any of the windows. The remaining unbroken windows become targets of petty criminal activity, which then spreads in various ways throughout an apathetic neighborhood. Since the presentation of this theory, many studies have confirmed its validity, including a 2008 study by K. Keizer and S. Lindenberg of University of Groningen.