Crime Statistics — The Uniform Crime Report

By 1929, the International Association of Chiefs of Police has come up with a system for measuring trends and rates of crime. A total of seven offenses in two categories, property and violent, are designated as Index crimes, or Part I offenses. Murder and non-negligent manslaughter, forcible rape, robbery, and aggravated assault are considered the violent offenses; burglary, larceny-theft, and motor vehicle theft are the property crimes. In 1979, arson will be added to the property category, bringing the total number of Index I crimes to eight. Additional crimes encountered by police are deemed Part II offenses.

Legislation passed by Congress in 1930 puts the U.S. attorney general in charge of gathering these national statistics, and the FBI is chosen to head the effort. The FBI collects the crime data (which also includes some demographic information about the defendants) from local police agencies and publishes it in a yearly report called Crime in the United States (popularly known as the Uniform Crime Report or UCR).

It is important to note that unsolved crimes are excluded from the report and that if an incident involves a variety of offenses, only the most serious one is recorded. The UCR becomes steadily more comprehensive. In the report's first year, 400 agencies send data to the FBI. By the end of the century, that number will have exploded to about 16,000. Whatever its faults, the UCR is extremely useful. Most crime stats reported in the media are from this source.

Carmine Napolitano, Unsolved Murder Mulberry St., 1938 Courtesy of NYC Municipal Archives