There is no consensus on whether the executing murderers has an effect on the homicide rate. Some say that it acts as a deterrent and reduces the murder rate in society; some say it has no effect; others say it may actually increase the rate.
There is a near consensus among experienced criminologists that executing murderers does not act as a deterrent. But many -- perhaps most -- of the public would strongly disagree.
People murder for a variety of reasons and under many different situations. Examples are murders:
during domestic disputes, when passions are inflamed
under the influence of alcohol or other drugs, when the perpetrator is not in full
by contract killers who are typically certain that they will never be caught
by psychopaths and other mentally ill individuals who have little regard for human life and
who are unable to accept responsibility for their actions
by self-destructive individuals who believe that they deserve to die and want to be
arrested and executed; and
by brain-damaged individuals, who experience periods of rage, and who, very rarely, may kill others.
With the exception of professional hit-men, very few people are in a rational frame of
mind when they kill others. It may be unreasonable to expect any form of punishment to act as
One very illuminating long-term study was conducted by Dorthy Otnow Lewis, a psychiatrist at New York University, and Dr Jonathan H. Pincus, chief of neurology at the Veterans Administration Hospital in Washington during the late 20th century. They spent over two decades studying over 150 death-row inmates and found that -- almost without exception -- their brains were severely damaged. Typically, they were viciously battered and often sexually abused as children. 1 Dr. Lewis concluded that most murders have damage to their frontal lobes which control a person's aggression and impulsiveness. Lewis and Pincus have published books on their findings. 2,3
Laura Mansnerus of the New York Times wrote of Lewis' findings:
"Many, she said, had been so traumatized that they could not remember how they had received their scars. The answers had to come from childhood medical records and interviews with family members. In another study, of 14 juveniles sentenced to death, the researchers found that all had suffered head trauma, most in car accidents but many by beatings as well. Twelve had suffered brutal physical abuse, five of those [were] sodomized by relatives. No one suggests that abuse or brain damage makes a murderer, but Dr. Lewis says that while most damaged people do not turn into killers, almost every killer is a damaged person." 1
However Barbara R. Kirwin, a forensic psychologist, has also studied murderers and came to a very different conclusion. She estimates that only about 10% of the 300 inmates she has studied have been abused. Many are sociopaths with competent brains who are simply devoid of empathy towards others.
No matter who is correct, one might argue that if murders are generally either sociopaths or brain-damaged, then the death penalty is unlikely to influence their behavior.
There are some indicators that the death penalty is not a deterent:
From 1976 to 1996, the number of executions per year in the United States has increased
from 0 to just under 60. The homicide rate per 100,000 population has remained constant at
just under 10. 4
In 1967, a study by Thorsten Sellin5 compared the homicide
rates between neighboring states in which some had the death penalty, and others did not.
Sellin also compared murder rates before and after states either abolished or reinstated
the death penalty. He found no statistically valid difference in rates in both cases.
These results were summarized in a book by J.Q. Wilson. 6The
study might have been affected by the numbers of executions at the time; they had dropped
to nearly zero in the U.S., so that even those states with death penalty laws on the books
were not exercising them fully.
In 1995, Professors Michael Radelet and Traci Lacock of the University of Colorado polled criminologists who belonged to the American Society of
Criminology, the Academy of Criminal Justice Sciences, and the Law and Society
Association. 83% believe that our current knowledge does not
indicate that the death penalty has a deterrent effect; 11.9% felt that it does. 75% felt that increasing the numbers of executions or
decreasing time spent on death row would not result in deterrence.7
Michael Radelet and Traci Lacock repeated the study in the late 2000's and reported their findings in a 2009 edition of the Journal of Criminal Law and Crimonology. They polled
Fellows in the American Society of Criminology (ASC),
Winners of the Sutherland Award -- the highest award given by the ASC for contributions to criminological theory, and
Presidents of the ASC between 1997 and the present.
Those polled were asked to base their conclusion on existing empirical research, not their views on capital punishment.
The percentage of expert criminologists who believe that the death penalty is not a deterrent rose to 88.2%; those who felt that it does act as a deterrant fell to 5.3% when compared to the 1995 study. Also:
91% of those surveyed believe that politicians support the death penalty in order to appear to be tough on crime.
75% say that debate on the death penalty distracts state legislatures and Congress from focusing on real solutions to crime.
88% say that speeding up executions wouldn't act as a deterrent either.
67% of the U.S. police chiefs polled in 1995 do not believe that the death penalty significantly reduces
the numbers of murders. 8
A 1998 research study conducted for the United Nations concluded:
research has failed to provide scientific proof that executions have a greater deterrent
effect than life imprisonment. Such proof is unlikely to be forthcoming. The evidence as a
whole still gives no positive support to the deterrent hypothesis." 9
There are some indicators that it does act as a deterrent:
In 1995, Peter D. Hart Research Associates conducted a national survey of randomly selected police chiefs. They ranked the death penalty as the least effective of 7 suggested methods of reducing
the homicide rate. 31% viewed reducing the usage of drugs as the most effective; 17% with
a better economy and more jobs, 16% by simplifying court rules; 15% with longer prison
sentences.....1% by expanding the use of the death penalty. 8
One writer 11 disagrees with the belief of most sociologists
The death penalty does not deter murderers.
Differing cultures in various states may
produce differing homicide rates.
Those states with the higher murder rates might also
be those which retain the death penalty.
He referred to:
A study by Isaac Ehrlich which found that the murder rate responded to changes in the
likelihood of execution. He concluded that 7 or 8 murders were prevented by each execution
from 1933 to 1967. 12,13
A study by Kenneth Wolpin which concluded that each execution, on average, reduced the
number of murders in England by 4. 14
Other articles and books have concluded that the death penalty does act as a deterrent: 15,16,17
There are some indicators that it acts as an anti-deterrent i.e. the death
penalty actually increases the homicide rate:
In 1996, the states which had the death penalty had an average murder rate of
7.1 per 100,000 population; those states which do not execute people had a homicide rate of 3.6. 4
Comparing adjacent states where one state has the death penalty and the other does not,
frequently shows that the states with capital punishment have a much higher homicide rate. 4
A report of the Bureau of Justice Statistics showed that during 1996, Southern
states, where about 81% of the executions are performed, have an average murder rate of 9
per 100,000 population. States in the Northeast are responsible for 1% of the executions
and have a murder rate of 5.4 4
Canada's homicide rate has dropped steadily since the death penalty was abolished in that
country (for ordinary crimes) in 1976. For many years prior to 1976, the federal
government had automatically converted each death sentence to life imprisonment.
In 2010, police reported 554 homicides in Canada producing a homicide rate of 1.62 per 100,000 population. Windsor, ON -- a city directly across the river from Detroit, MI had zero murders during 2009 and 2010. 20
A 1980 study of homicides in New York found that the average numbers of murders
increased in the month following an execution 18
A 1995 study of the annual percentage increases in homicide rates in California showed
that murders increased 10% a year during 1952 to 1967 when the state was executing people.
When the state performed no executions (1968-1991) the average rate of increase was less
The FBI Uniform Crime Reports Division publication Crime in the US
for 1995 reports thatthere were 4.9 murders per 100,000 people in states
that have abolished the death penalty, compared with 9.2 murders in those states which
still have the death penalty. "In no state has the number of murders diminished
after legalizing the death penalty." 19
Some commentators assume that there is a cause and effect relationship between the death penalty and the homicide rate. They may reason that if the state considers human life to be of so little value that it is acceptable for the state to kill people, then the public may lower the value that it assigns to human life. Executions cheapen life.
On the other hand, the opposite may be true. In those states where the homicide rate is already high because of poverty, high unemployment, high drug use, a violent culture, etc., then perhaps the public is desperate enough to want to try executing people in the hope that it might lower the homicide rate. They may find comfort in the fact that a dead murder will never execute another person in the future.