Cook Philip J, Ludwig Jens, Braga Anthony A
Department of Public Policy Studies, Duke University, Durham, NC 27708-0245, USA.
JAMA. 2005 Aug 3;294(5):598-601. doi: 10.1001/jama.294.5.598.
Homicide prevention strategies can be either targeted toward high-risk groups or addressed to the population at large. One high-risk group of particular interest is adults with a criminal record. But the prevalence of a criminal record among homicide offenders has not been reliably quantified, nor has the prevalence of criminal record in the general population.
To determine what portion of the homicide problem would be addressed by interventions linked to arrest or conviction.
DESIGN, SETTING, AND PARTICIPANTS: A case-control analysis was performed using a comprehensive data set of all arrests and felony convictions in Illinois for 1990-2001. Cases were defined as Illinois residents aged 18 to 64 years who were arrested for homicide in 2001. Controls were all other Illinois residents aged 18 to 64 years in 2001. Illinois criminal and juvenile record information for cases and controls was compiled for 1990-2000. Five definitions of previous record were considered (arrest, arrest for a violent crime, 5 or more arrests with at least 1 for a violent crime, felony conviction, and violent-felony conviction), each measured for 1990-2000 and for 1996-2000.
The population-attributable risk: the portion of homicide offenses that would be eliminated by a hypothetical intervention that reduced the offending risk of individuals with a record to the offending risk of those who lack a record.
For 1990-2000, 42.6% of 884 cases had at least 1 felony conviction compared with 3.9% of nearly 7.9 million controls, for a population-attributable risk of 40.3% (95% CI, 37.0%-43.8%); among cases, 71.6% had experienced any arrest from 1990-2000 compared with 18.2% of controls, for a population-attributable risk of 65.3% (95% CI, 61.6%-68.8%). For 1996-2000, the population-attributable risk among individuals with a felony conviction or any arrest was 31.0% (95% CI, 27.9%-34.2%) and 58.5% (95% CI, 54.9%-62.1%), respectively.
Interventions after arrest or conviction, such as supervised release, imprisonment, correctional programs, or bans on firearm possession, are targeted toward a group that has relatively high incidence of lethal violence, but they leave a large portion of the problem untouched.
预防杀人犯罪的策略既可以针对高危群体,也可以面向广大民众。一个特别值得关注的高危群体是有犯罪记录的成年人。但是,杀人犯罪者中有犯罪记录的比例尚未得到可靠量化,普通人群中有犯罪记录的比例也未可知。
确定与逮捕或定罪相关的干预措施能够解决多大比例的杀人犯罪问题。
设计、地点和参与者:采用1990年至2001年伊利诺伊州所有逮捕和重罪定罪的综合数据集进行病例对照分析。病例定义为2001年因杀人罪被捕的18至64岁伊利诺伊州居民。对照为2001年所有其他18至64岁的伊利诺伊州居民。收集了1990年至2000年病例和对照的伊利诺伊州刑事和少年犯罪记录信息。考虑了既往记录的五种定义(逮捕、暴力犯罪逮捕、5次或更多次逮捕且至少1次为暴力犯罪逮捕、重罪定罪、暴力重罪定罪),分别针对1990年至2000年以及1996年至2000年进行测量。
人群归因风险:通过假设干预将有记录者的犯罪风险降低至无记录者的犯罪风险后,可消除的杀人犯罪比例。
1990年至2000年,884例病例中有42.6%至少有1次重罪定罪,而近790万对照中有3.9%,人群归因风险为40.3%(95%可信区间,37.0% - 43.8%);在病例中,71.6%在1990年至2000年有过任何逮捕,而对照中这一比例为18.2%,人群归因风险为65.3%(95%可信区间,61.6% - 68.8%)。1996年至2000年,有重罪定罪或任何逮捕者的人群归因风险分别为31.0%(95%可信区间,27.9% - 34.2%)和58.5%(95%可信区间,54.9% - 62.1%)。
逮捕或定罪后的干预措施,如监督释放、监禁、矫正项目或禁止持有枪支,针对的是致命暴力发生率相对较高的群体,但仍有很大一部分问题未得到解决。