uide for Implementing the Comprehensive Strategy for Serious ...

chronic violent offenders during adolescence. However,
among those who began committing violent
offenses between ages 10 and 12, 30 percent became
chronic violent offenders. The Denver findings were
more striking. Of those who initiated violent behavior
at age 9 or younger, 62 percent became chronic
violent offenders. On average, the chronic violent
offenders began offending a full year prior to those
who did not become chronic offenders.
A large proportion of those who
are involved in violent behavior at
an early age eventually become
chronic violent offenders.
Chronic Offending
In Rochester, a total of 5,504 violent acts were selfreported
by the respondents. Of these, nonchronic
violent offenders up to ages 17 and 18 reported 1,370
violent offenses, or an average of 3.9 per person. On
the other hand, chronic violent offenders reported a
total of 4,134 violent crimes, an average of 33.6 per
person. Denver respondents up to ages 17 and 18
reported 5,164 violent acts. Of these, 927 violent
offenses were committed by nonchronic offenders, an
average of 4.5 per person; 4,237 violent offenses were
committed by chronic offenders, an average of 51.7
per person.
Prevalence Rates
Preliminary analyses of serious violent prevalence
rates (percentage of boys who self-report serious violent
offenses) show a different pattern than has been
found in other studies of individual offending. Previous
studies have found male prevalence rates to peak
at ages 16 to 17, unlike arrest rates, which generally
have been found to peak at ages 18 to 19. However,
data from these three sites have shown no decline in
male self-reported serious violent offending in late
adolescence. These prevalence rates remain high (17
to 20 percent) during the 17 to 19 age period. Whether
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an anticipated downward age curve will be found for
males in the future requires analysis of additional
years of data that are being collected at each site.
Co-Occurring Problem Behaviors
All three studies showed that chronic violent offenders
not only engaged in multiple types of offenses but also
in a variety of other problem behaviors. These youth
have higher rates of dropping out of school, gun ownership
for protection, gun use, gang membership, teenage
sexual activity, teenage parenthood, and early
independence from their family. In Rochester, nearly
two-thirds of chronic violent offenders reported being
members of street gangs. During the period of gang
membership among juveniles in Rochester and Denver,
levels of involvement in violence were much
higher than during the periods before and after gang
membership.
The Rochester site examined the relationship between
exposure to family violence and later involvement in
youth violence. Not only was greater risk for violent
offending found to exist when a child was physically
abused or neglected early in life, but such children
were more likely to begin violent offending earlier and
to be more involved in such offending than children
who had not been abused or neglected. Second, this
research revealed that children who witnessed and
experienced multiple acts of violence in the home
(child abuse, spouse abuse, and family conflict) were
twice as likely to commit violent acts themselves
(Thornberry, 1994).
Multiple Risk Factors
These three studies have also confirmed earlier research
showing that serious, violent, chronic juvenile
offenders have multiple risk factors. No single risk
factor is responsible for serious delinquency and violence.
Chronic offenders have multiple risk factors in
their backgrounds, including deficits in such arenas as
family, school, peers, and neighborhood characteristics.
Moreover, these factors tend to be cumulative and
to interact with one another to produce high levels of
serious offending.