138 Years of Murder in Chicago

Unlike other posts on this site, this one focuses not on a single crime scene or an historical account of one or two individuals, but instead summarizes the facts on over a century of murder in Chicago. One of the main purposes of this blog is to understand Chicago's historic and modern reputation for crime, and comparisons over time can be illuminating.

The figure above shows the city's murder rate, expressed as murders per 100,000 residents, between 1870 and 2008. This gives a long-run summary view of homicide in Chicago over the last 138 years. I focus here on murder because, unlike rape, larceny, and other crimes, the likelihood of unreported victims is less severe with murder. The cops will eventually notice every corpse lying in the street, although it is true that some "accidental" deaths may actually have been murders, and some bodies are never found.

Data from 1931 to the present is drawn from the FBI's annual Crime in the United States, and is based on reports from local police agencies. Figures from 1870 - 1930 are based on Chicago police department data processed by Homicide in Chicago, a project hosted at Northwestern University School of Law. All figures include both murders and non-negligent manslaughter.

Between 1870 and 1920, Chicago's crime rate grew at an essentially steady pace, reaching a peak of 10 per 100,000 in 1919. During this period, Chicago was growing in population and density. High population density is typically associated with greater crime rates for several reasons. First, in small towns, every face is familiar, but in large cities, criminals are less likely to be recognized by witnesses. Realizing a lower likelihood of being caught, criminals commit more crimes. Second, crime pays better in cities, because there are more people to rob -- there's no point in becoming a robber in the first place if you can't hit lots of targets. Finally, and especially relevant to Chicago during this period, big cities attract large communities of poor immigrants with few prospects for legal employment. Criminal, on the other hand, is a profession open to all.

With the onset of national Prohibition in 1919, many of these immigrants gained lucrative employment in the bootlegging field, and for the first few years of the 1920s, at least, murder rates fell by nearly 50%. But as the various parts of Johnny Torrio's syndicate began falling apart in 1924, culminating in the murder of Torrio's north side associate Dion O'Banion, likely at the hand of his south side associates, the Genna brothers, Chicago's "Beer Wars" began, and the murder rate skyrocketed by 250% between 1923 and 1928. Also around the same time, the notoriously-violent Al Capone took over full control of Torrio's organization in 1925.

Even as Prohibition ended in 1931, murder rates remained high throughout the early 1930s, the worst years of the Great Depression, before falling below 5 per 100,000 in 1943. No doubt the massive mobilization of American men out of Chicago and into military companies in army barracks and overseas locations played no small role in the low murder rates of the early 1940s -- men have traditionally constituted the vast majority of both murderers and murder victims.

After WWII, Chicago's murder rate again began to climb as the city continued growing in size until around 1950. The city's demographics also changed during this period, as increasing automobile ownership and better highways allowed families seeking larger homes to commute from the suburbs, while younger cohorts without children remained in the city (most murderers are drawn from the ranks of 17-24 year olds).

Between 1943 and 1965, Chicago's murder rate rose at a roughly constant rate, increasing by 1 per 100,000 about every three years. However, between 1965 and 1970, the murder rate rose much more dramatically, increasing from 11 per 100,000 in 1965 to 24 per 100,000 in 1970.

Why did the murder rate rise so quickly in the late 1960s? Some point to stricter standards for policing and stronger rights for accused criminals during this period, symbolized by the Miranda case in 1966, in which the Supreme Court ruled that the police must inform arrested persons of their rights before interrogating them. Criminals facing a lower probability of punishment rationally commit more crimes.

There is also some evidence that the generation born after World War II had substantially poorer family formation rates, with an increasing share of children growing up in single-parent households. As I've written elsewhere, as these children reached their late teens and early adulthood -- when offense rates are highest -- in the late 1960s, the quantity of violent crime rose proportionately.

Another potential factor in the growth of crime during this era was the changing consumption patterns and legal status of drugs. The use of heroin and psychodelic drugs increased during the 1960s as production and transportation costs fell, and these drugs also become especially popular among enlisted men and counterculture communities. The pharmacological effects of increased drug consumption -- at least among the class of drugs popular during this period -- on violence are debatable. However, increased usage also led to substantially greater levels of enforcement. Federal prohibition on heroin stretches back to the 1910s, but LSD only became illegal in 1966. Arrests for drug crimes, which were exceptionally rare before 1965, skyrocketed afterwards. With prohibition comes incentives for violence between customers, dealers, and suppliers, who can no longer depend on the courts and police to enforce contracts and mitigate violence.

The war on drugs continued through the 1970s and 1980s. Especially prominent as a source of crime is the arrival of crack cocaine in the mid-1980s. Crack was an immediately and immensely popular drug, and its arrival in Chicago kicked off massive and bloody turf wars among rival drug-selling organizations (primarily street gangs) for control of retailing markets in the city.

While crack consumption has not waned much since the 1980s, boundaries between rival sellers have largely been settled. Thus, the end of the "crack epidemic" coincided with big declines in Chicago's murder rate. In the mid-1990s, the murder rate in Chicago (and nationwide) fell dramatically, declining below 50% of its 1992 peak by 2004. Besides the end of the crack epidemic, there are potentially several causes for this remarkable turnaround.

In other cities, such as New York, declines in crime have been attributed to substantial increases in the number of police on the street and to creative policing strategies. Chicago, however, saw little change in the size of its police force, and "broken windows" and other techniques were slow in gaining acceptance at the CPD, although greater efforts towards community engagement, such as the CAPS program, did begin in the early 1990s.

Imprisonment rates also increased during this period, with Illinois holding 27,516 prisoners in 1990 and 45,281 in 2000. With more criminals behind bars, there are fewer on the street committing crime. In addition, an increased likelihood of a lengthy prison sentence likely deters some would-be criminals.

Finally, and most controversially, some researchers have recently pointed to the role of legalized abortion in the evident decline in crime during the 1990s. While some states legalized abortion procedures before 1973, Illinois and most other states saw legalization after the Supreme Court's famous Roe v. Wade decision that year. A large share of women seeking abortions do so because they feel unprepared to raise a child -- and no doubt many of them in fact are poorly prepared for motherhood. After the legalization of abortion, this theory argues, many children, who would have been raised in high-risk environments, were never born. This "missing cohort" would have reached their late teens and early 20s during the early 1990s; thus, the decline in murder rates in the 1990s may be partially due to the fact that many would-be murderers were never born.

The statistical evidence regarding this theory is controversial and, in many places, contradictory. Nevertheless, it is difficult to doubt that at least some of the decline in Chicago's murder rate during the 1990s is due to legalized abortion.

By 2008, Chicago's murder rate was 18.03 per 100,000, roughly the same as it was in 1967. Nevertheless, the city's rate is substantially higher than some other large cities, including New York City (6.3 per 100,000) and Los Angeles (10.0 per 100,000). On the other hand, Chicago is relatively safe compared with Philadelphia (23.0 per 100,000), Detroit (33.8 per 100,000), and Gary, Indiana (73.2 per 100,000).