DÄ internationalArchive41/2014Violent Crime Perpetrated by Young People

Original article

Violent Crime Perpetrated by Young People

Results of a 13-Year Longitudinal Study of Offenders on Probation

Dtsch Arztebl Int 2014; 111: 685-91. DOI: 10.3238/arztebl.2014.0685

Remschmidt, H; Martin, M; Niebergall, G; Heinzel-Gutenbrunner, M

Background: The goal of this study was to follow the further legal development of young people who undergo adolescent psychiatric and psychological assessment because of an attempted or actual homicide and are convicted of the crime. We were able to do this over a mean follow-up duration of 12.8 years after conviction through the use of excerpts from the German Federal Central Register (Bundeszentralregister).

Methods: There were 114 offenders (103 male, 11 female), whose age at the time of the offense was 17.6 ± 1.9 years (mean, standard deviation). They underwent assessment in an overall period of nearly 31 years after taking the lives of 70 persons. 30 of the offenders (26.3%) had committed the violent crime as part of a group of offenders. We assessed their further course on the basis of data from psychiatric and psychological expert assessments, court judgments, and excerpts from the Federal Central Criminal Register and the Educational File.

Results: 92 (80.7%) of the offenders were German citizens, 12 (10.5%) were from immigrant families, and 22 (19.3%) were foreigners. In 96 cases (84.2%), a psychiatric diagnosis was made at the time of assessment; this was not the case for only 18 individuals (15.8%). 20 (17.5%) were admitted to a psychiatric hospital or drug withdrawal clinic. 44 (38.6%) developed into chronic criminal offenders who continued to commit crimes after the index offense. As a subgroup of the chronic criminal offenders, 13 individuals (11.4% of the overall sample) were identified as multiple intensive offenders; these individuals displayed the most extreme features in every respect. A total of 70 individuals (61.4%) no longer came to the attention of the criminal justice system during the entire duration of follow-up after the index offense. The legal prognosis test was able to predict the offenders’ further course with statistical significance, but not accurately enough to be safe.

Discussion: The high rate of mental disorders (84.2%) is noteworthy and in accordance with other, comparable studies. This finding implies that more importance should be attached to psychiatric and psychological diagnosis and treatment. We did not find any limitation of cognitive function in our group of subjects, even though this has been reported in multiple studies in the literature. The intelligence of our subjects was normally distributed.

LNSLNS

According to police crime statistics, which are figures on suspects, in the last 20 years there has been no increase in the number of killings perpetrated by young people in Germany (aged 14 to 20) and a slight drop in crimes resulting in physical injury (1). Figures on convicted individuals also show this trend (2).

Turning to the circumstances that give rise to violent crime (Figure 1), there are three groups of factors involved in causing or triggering violence (3):

Different routes to manifestation of violent behavior
Different routes to manifestation of violent behavior
Figure 1
Different routes to manifestation of violent behavior
  • Biological or neurobiological risk factors (e.g. male sex, autonomic reactivity abnormalities)
  • Psychological and social risk factors (e.g. low intelligence, school failure, unfavorable family relationships, neuropsychological deficits)
  • Situational influences (e.g. alcohol and drug use, possession of weapons, group dynamics).

Numerous studies have shown the effect of all three of these groups of factors in causing and triggering violent behavior. However, their contribution is unquantifiable, not least because there are many interactions between them (details in [3] and the eSupplement, including eFigures 1 and 2, eBox).

Causes of violence
Causes of violence
eBox
Causes of violence
ROC curve: LDJ as predictor of slightly violent reoffending. LDJ: Legal Prognosis Test
ROC curve: LDJ as predictor of slightly violent reoffending. LDJ: Legal Prognosis Test
eFigure 1
ROC curve: LDJ as predictor of slightly violent reoffending. LDJ: Legal Prognosis Test
Time to reoffending: next offense of perpetrators with burdens rated high and low according to the LDJ (Legal Prognosis Test)
Time to reoffending: next offense of perpetrators with burdens rated high and low according to the LDJ (Legal Prognosis Test)
eFigure 2
Time to reoffending: next offense of perpetrators with burdens rated high and low according to the LDJ (Legal Prognosis Test)

Manifestation of violent behavior

Figure 1 shows that violent behavior can either follow antisocial behavior and nonviolent crime or occur with no intermediate stages. An example of the latter is a crime of passion: these are almost always the culmination of previous confrontations and not infrequently result in a killing, committed by someone who commits no other crimes before or afterwards (case 70: crime of passion resulting in patricide, Box 1).

Three example crimes: one crime of passion and two crimes by multiple serious offenders
Three example crimes: one crime of passion and two crimes by multiple serious offenders
Box 1
Three example crimes: one crime of passion and two crimes by multiple serious offenders

Young people and adolescents who are charged with murder or attempted murder in Germany almost always undergo adolescent psychiatric and/or psychological examination. However, there is a lack of long-term longitudinal data for this group.

Question investigated

The aim of this study was to follow the legal development of young people who had undergone adolescent psychiatric and psychological examination as a result of committing murder or attempted murder and on whom final sentence had been passed.

Methods

Study and sample design

The study design is shown in Figure 2. The starting point was the index act, the reason a particular individual underwent assessment. The expert assessment was explained or supplemented during trial and in most cases made a major contribution to the verdict found. After they were sentenced to imprisonment or found not to be criminally culpable or to be culpable to only a limited extent, and admitted to a psychiatric hospital according to Article 63 of the German penal code or a detoxification clinic according to Article 64 of the German penal code, the perpetrators’ subsequent legal development was followed using extracts from Germany’s Federal Central Criminal Register for an average of 154 months (approximately 12.8 years). This allowed us to identify the offender type groups shown in Figure 2, based on crimes committed before and after the index act. However, these could only be identified retrospectively, after extracts from the Federal Central Criminal Register had been obtained.

Design of the Marburg violent crime study
Design of the Marburg violent crime study
Figure 2
Design of the Marburg violent crime study

Figure 2 shows that a mean of 8 ± 7.3 months elapsed between the index act and examination, and that the mean time from examination to trial was also more than six months (6.1 ± 7.5).

This study includes only medical certificates of individuals who had been sent by court order to the Department of Child and Adolescent Psychiatry and Psychotherapy at Philipps University, Marburg for examination after committing serious violent crime between 1976 and 2007. It includes a total of 114 perpetrators, 103 male and 11 female, aged 17.6 ± 1.9 years (range: 14 to 21 years). The youngest perpetrators were nine 14-year-olds. All individuals were examined by two experienced child and adolescent psychiatrists (H.R. and M.M.). The psychological examinations carried out as part of medical certification were performed by an experienced clinical psychologist and psychotherapist (G.N.).

Crimes committed by 114 perpetrators
Crimes committed by 114 perpetrators
Table 1
Crimes committed by 114 perpetrators

Psychiatric diagnoses were made according to the Multiaxial Classification Scheme for Child and Adolescent Psychiatric Disorders (MAS) (Remschmidt et al., 2012 [4] or earlier versions; see also: World Health Organization (ed.): Multiaxial classification of child and adolescent psychiatric disorders. World Health Organization, Cambridge: Cambridge University Press 1996), using the ICD-10 research criteria (5). As ICD-10 was not published until 1991, diagnoses made according to ICD-9 before that date were re-coded according to ICD-10. As shown in Table 1, the most common crime was murder, which accounted for 36.8% of cases, followed by manslaughter at 11.4%.

The examination methods and statistical tests used are shown in Box 2.

Examination methods and statistical procedures used
Examination methods and statistical procedures used
Box 2
Examination methods and statistical procedures used

Results

Total sample

Table 2 provides an overview of the sociodemographic data of the 114 perpetrators. Table 3 provides an overview of the psychiatric diagnoses of the sample as a whole. Strikingly, only 18 perpetrators (15.8%) failed to meet the criteria for a psychiatric diagnosis according to ICD-10.

Sociodemographic details of 114 perpetrators
Sociodemographic details of 114 perpetrators
Table 2
Sociodemographic details of 114 perpetrators
ICD-10 psychiatric diagnoses of 114 perpetrators
ICD-10 psychiatric diagnoses of 114 perpetrators
Table 3
ICD-10 psychiatric diagnoses of 114 perpetrators

Crime-based and perpetrator-based subsamples

Extracts from the Federal Central Criminal Register or Educational File were used to identify offender type retrospectively and to follow perpetrators’ legal development prospectively (see Figure 2). Even individuals with only one entry in the register (group A, n = 34) committed serious crimes. Of these, 21 (62%) led to the death of the victim, usually as a result of murder. The perpetrators in this group who had committed murder included two 14-year-olds. Despite the seriousness of their crimes, individuals with only one entry (group A) were rated as less abnormal according to the Marburg Symptom Rating than those with multiple entries (groups B and C). The differences concerned symptoms of antisocial behavior, aggression, poor performance, and symptoms of hyperactivity.

There were no differences between the Marburg Symptom Rating scores of the desisters in the sample (group B) and those of the persisters (group C) except for symptoms of anxiety, which were rated significantly lower in group C. There were no significant differences in intelligence between the three groups.

Table 4 compares the Marburg Symptom Rating scores of the three offender type groups. It is important to bear in mind that the Marburg Symptom Rating scores were obtained during medical certification, i.e. an average of 12.8 years before the offender type groups were identified. Within the group of persisters was a subgroup of multiple intensive offenders (n = 13). Members of this subgroup committed more than 30 crimes and/or had more than 10 entries in the central register, regardless of when these events occurred. This definition is supported by similar procedures in the literature; as yet there is no universally accepted definition of this subgroup (9).

Comparison of psychological abnormalities (according to the Marburg Symptom Rating) of the three crime burden groups
Comparison of psychological abnormalities (according to the Marburg Symptom Rating) of the three crime burden groups
Table 4
Comparison of psychological abnormalities (according to the Marburg Symptom Rating) of the three crime burden groups

Multiple intensive offenders were the most abnormal subgroup in many different respects: nine of the 13 individuals had committed a killing, including six acts of murder. They differed significantly from offenders with one register entry in terms of their overall Marburg Symptom Rating scores (ANOVA) (group A, t-test, p<0.03) and overall Legal Prognosis Test (LDJ, Legal Prognosis Test for Dissocial Youth) scores (group A, t-test, p<0.001); there was a trend when compared to desisters (group B, t-test, p = 0.06). The difference was always greater abnormality in multiple serious offenders. Two examples are described in Box 1 (case 28: killing of a homosexual man by a youth; case 114; group murder of a pensioner).

The only other perpetrator-based subgroup to be mentioned here is that of perpetrators who acted together with others (n = 30). Group dynamics led to a higher killing rate in this subgroup than among perpetrators who acted alone. Group dynamics are very significant in leading to crime among individuals of the ages analyzed in this article.

A prototypical example of this occurred in 2002, when three US school students (aged 15, 17, and 18) threw stones at an approaching vehicle in the darkness of a highway bridge, resulting in the deaths of two women. The three perpetrators, who were psychologically normal, intelligent, and fully culpable, had largely blotted out the dangerous nature of their behavior as part of an increasing group dynamic process involving “tests of courage.” Ultimately, like their parents and the general public (the case was widely reported in the press), they were shocked by what they had done. They were sentenced to imprisonment for 7 years, 8 years, and 8½ years in a young offenders’ institution for two counts of murder and were released after serving two-thirds of that time in the USA. It is not known whether they have committed any further crimes.

Of the total sample of perpetrators, 20 (17.5%) were admitted to a psychiatric hospital or detoxification clinic (n = 3.5%) for their disorders. Thirty-seven perpetrators (32.5%) committed their violent acts under significant influence of alcohol and/or drugs. In 22 cases (19.3%) the victim was a relative; 14 of these resulted in the relative’s death, including one case of the killing of both parents and the sister of the perpetrator, and one case of the killing of both parents by a contract killer.

The mean number of crimes committed was 10.5 ± 12.6, with a maximum of 72. The mean number of entries in Germany’s central register was 4.3 ± 4.2, with a maximum of 22.

The intelligence of the total sample (mean IQ: 101 ± 17) was normally distributed; IQ scores ranged from 50 to 143; five perpetrators (4.4%) had an IQ of between 50 and 69, and six (5.3%) of more than 130.

Longitudinal results and prognosis

As already described and shown in Figure 2, 44 (38.6%) of the perpetrators committed subsequent crimes, becoming persisters, during the observation period; this lasted 12.8 years following their index act. Half the perpetrators committed further violent crime, and half a number of other crimes, especially damage to property, traffic offenses, and breaches of controlled substances legislation. The violent reoffending rate was 19.3%. None of the persisters committed a further killing.

The legal prognosis test for antisocial young people (LDJ) developed by Hartmann and Eberhard (8) was used at the time of examination to assess reoffending over time. This test includes 11 items. It was published in 1972 and was used to provide uniformity between examination tools, since this study covered examinations made over a period of 31 years and newer prognosis tools were not available until the 1990s. ROC analyses showed that the LDJ does make a contribution to predict violent reoffending, although only a small one. Details are provided in the eSupplement.

Discussion

The sociodemographic data of the sample is typical for young adult and adolescent perpetrators. However, there was no major overrepresentation of lower social classes. The correlation between mildly reduced intelligence and crime, which has been described many times in the literature, could not be confirmed (10, 11); the correlation had been found even for unrecorded crime (hidden figures) (12). IQ was normally distributed in this sample.

Subsequent criminal behavior was recorded for 44 (38.6%) of persisters; half of these cases involved violent crime, and half nonviolent crime. These results correspond almost exactly to those of a similar sample analyzed by Günter et al. (13, 14), who after a longer follow-up period found reoffending rates of 38% for all crimes and 20% for violent crime. The other 70 perpetrators did not commit any further crimes during the observation period, according to the central register.

In the study of crime committed by children, in which a representative sample (n = 210) of children too young to be charged was followed for a period of approximately 30 years, there were 68 persisters (32.4%). The number of perpetrators of violent crime in the total sample was 33 (15.7%); the number among the persister subgroup was 24 (35.3%) (15, 16).

The high proportion of perpetrators with psychiatric diagnoses found in our sample is in line with comparable studies that found psychiatric diagnoses in 90% of prisoners in young offenders’ institutions (17, 18).

Limitations

Although the sample of perpetrators used in this study may be considered unrepresentative (in any case no such representative sample exists), a sample of this size can be assumed to contain the most common constellations of criminal acts for the age group addressed here. This means that to a certain extent the results for the sample can be generalized. One point of criticism may be that some tests (e.g. IQ tests) were revised during the long study period. Even psychiatric diagnoses have changed, namely when ICD-9 was replaced by ICD-10 in 1991. This gave rise to the need to recode ICD-9 diagnoses as ICD-10 diagnoses. In addition, register data naturally cannot provide any information on undetected crimes. These limitations must be accepted. However, we believe that the underlying conclusions drawn from the study are not affected by this. Against criticism of the methods used, there are a number of advantageous factors: personal knowledge of all perpetrators, and in most cases also of their parents or role models; and the use of the same examination methods throughout the study period.

Acknowledgement
We would like to thank the management of the German Federal Office of Justice for their permission to include data from the Federal Central Criminal Register and Educational Files in their evaluations.

Conflict of interest statement

Prof. Remschmidt received fees for providing expert forensic opinions for the courts.

PD Dr. Martin received fees for providing expert forensic opinions for the courts.

Dr. Niebergall received fees for providing expert forensic certification for the courts.

Dr. Heinzel-Gutenbrunner declares that no conflict of interest exists.

Manuscript received on 28 August 2012, revised version accepted on 24 July 2014.

Translated from the original German by Caroline Devitt, M.A.

Corresponding author:
Prof. Dr. med. Dr. phil. Helmut Remschmidt
Klinik für Kinder- und Jugendpsychiatrie, Psychosomatik
und Psychotherapie der Philipps-Universität
Schützenstr. 49, 5039 Marburg, Germany
remschm@med.uni-marburg.de

@For eReferences please refer to:
www.aerzteblatt-international.de/ref4114

eSupplement, eFigures, eBoxes:
www.aerzteblatt-international.de/14m0685

1.
Bundeskriminalamt (eds.): Bundeskriminalstatistik. Wiesbaden: Bundeskriminalamt 2013.
2.
Statistisches Bundesamt (eds.): Verurteiltenstatistik. Wiesbaden: Statistisches Bundesamt 2013.
3.
Remschmidt H: Tötungs- und Gewaltdelikte junger Menschen. Ursachen, Begutachtung und Prognose. Heidelberg: Springer 2012.
4.
Remschmidt H, Schmidt M, Poustka F (eds.): Multiaxiales Klassifikationsschema für psychische Störungen des Kindes- und Jugendalters nach ICD-10 der WHO, 6th edition. Bern: Huber 2012.
5.
Dilling H, Mumbour W, Schmidt MH, Schulte-Markwort E (eds.): Internationale Klassifikation psychischer Störungen nach ICD-10, Forschungskriterien. Bern: Huber 1994.
6.
Mattejat F, Remschmidt H: Marburger Symptom Rating (MSR). Standardisiertes Elterninterview zur Erfassung psychopathologischer Auffälligkeiten von Kindern und Jugendlichen. Bern: Huber 2010.
7.
Rutter M, Quinton D: Psychiatric disorder: ecological factors and concepts of causation. In: McGurk M (ed.): Ecological factors in Human Development. Amsterdam: North Holland Publisher 1977; 173–87.
8.
Hartmann K, Eberhard K: Legalprognosetest für dissoziale Jugendliche (LDJ). Göttingen: Verlag für Medizinische Psychologie im Verlag Vandenhoeck und Ruprecht 1972.
9.
Sonka C, Riesner L: Junge „Mehrfach- und Intensivtäter – Implikationen für die Auswahl in polizeiliche Programme“. Forensische Psychiatrie, Psychologie, Kriminologie 2012; 6: 119–27. CrossRef
10.
Wolfgang ME, Figlio RM, Sellin T: Delinquency in a birth cohort. Chicago: University of Chicago Press 1972.
11.
Lynam D, Moffitt TE, Stouthamer-Loeber M: Explaining the relation between IQ and delinquency: Class, race, test motivation, school failure, or self-control? Journal of Abnormal Psychology 1993; 102: 187–96. CrossRef MEDLINE
12.
Moffitt TE, Caspi A, Silva PA, Stouthamer-Loeber M: Individual differences in personality and intelligence are linked to crime. Cross-context evidence from nations, neighborhood, genders, races, and age-cohorts. In: Smith Blau Z (eds.): Current perspectives on aging and the life cycle. Delinquency and disrepute in the life course. Greenwich: JAI Press Inc. 1995; 4: 1–34.
13.
Günter M, Eistetter S, Kern D: Jugendliche und heranwachsende Tötungsdelinquente. Charakteristika aus der psychiatrischen Begutachtung und späteres Rezidivrisiko. In: Duncker H, Koller M, Foerster K (eds.): Forensische Psychiatrie – Entwicklung und Perspektiven. Ulrich Venzlaff zum 85. Geburtstag. Längerich: Pabst-Science-Publishers 2006: 145–62.
14.
Günter M, Eistetter S, Kern D: Jugendliche und heranwachsende Tötungsdelinquente. Charakteristika aus der psychiatrischen Begutachtung und späteres Rezidivrisiko. Forens Psychiatrie Psychother 2009; 2: 52–69.
15.
Remschmidt H, Walter R: Kinderdelinquenz. Gesetzesverstöße Strafunmündiger und ihre Folgen. Heidelberg: Springer 2009.
16.
Remschmidt H, Walter R: What becomes of delinquent children? Results of the Marburg Juvenile Delinquency Study. Dtsch Arztebl Int 2010; 107: 477–83. VOLLTEXT
17.
Vreugdenhil C, Doreleijers TAH Vermeiren R, Wouters LFJM, van den Brink W: Psychiatric disorders in a representative sample of incarcerated boys in the Netherlands. Journal of the American Academy of Child and Adolescent Psychiatry 2004; 43: 97–104. CrossRef MEDLINE
18.
Plattner B, Aebi M, Steinhausen HC, Bessler C: Psychopathologische und komorbide Störungen inhaftierter Jugendlicher in Österreich. Zeitschrift für Kinder- und Jugendpsychiatrie und Psychotherapie 2011; 39: 231–42. CrossRef MEDLINE
e1.
Hosmer DW, Lemeshow S: Applied Logistic Regression (2nd edition). New York: Wiley 2000.
e2.
Zwiener I, Blettner M, Hommel G: Survival analysis—part 15 of a series on evaluation of scientific publications. Dtsch Arztebl Int 2011; 108: 163–9. VOLLTEXT
Department of Child and Adolescent Psychiatry, Philipps University, Marburg: Prof. Dr. med. Dr. phil. Remschmidt, PD Dr. med. Martin, Dr. Dipl.-Psych. Niebergall, Dr. Dipl.-Stat. Heinzel-Gutenbrunner
Three example crimes: one crime of passion and two crimes by multiple serious offenders
Three example crimes: one crime of passion and two crimes by multiple serious offenders
Box 1
Three example crimes: one crime of passion and two crimes by multiple serious offenders
Examination methods and statistical procedures used
Examination methods and statistical procedures used
Box 2
Examination methods and statistical procedures used
Different routes to manifestation of violent behavior
Different routes to manifestation of violent behavior
Figure 1
Different routes to manifestation of violent behavior
Design of the Marburg violent crime study
Design of the Marburg violent crime study
Figure 2
Design of the Marburg violent crime study
Crimes committed by 114 perpetrators
Crimes committed by 114 perpetrators
Table 1
Crimes committed by 114 perpetrators
Sociodemographic details of 114 perpetrators
Sociodemographic details of 114 perpetrators
Table 2
Sociodemographic details of 114 perpetrators
ICD-10 psychiatric diagnoses of 114 perpetrators
ICD-10 psychiatric diagnoses of 114 perpetrators
Table 3
ICD-10 psychiatric diagnoses of 114 perpetrators
Comparison of psychological abnormalities (according to the Marburg Symptom Rating) of the three crime burden groups
Comparison of psychological abnormalities (according to the Marburg Symptom Rating) of the three crime burden groups
Table 4
Comparison of psychological abnormalities (according to the Marburg Symptom Rating) of the three crime burden groups
Causes of violence
Causes of violence
eBox
Causes of violence
ROC curve: LDJ as predictor of slightly violent reoffending. LDJ: Legal Prognosis Test
ROC curve: LDJ as predictor of slightly violent reoffending. LDJ: Legal Prognosis Test
eFigure 1
ROC curve: LDJ as predictor of slightly violent reoffending. LDJ: Legal Prognosis Test
Time to reoffending: next offense of perpetrators with burdens rated high and low according to the LDJ (Legal Prognosis Test)
Time to reoffending: next offense of perpetrators with burdens rated high and low according to the LDJ (Legal Prognosis Test)
eFigure 2
Time to reoffending: next offense of perpetrators with burdens rated high and low according to the LDJ (Legal Prognosis Test)
1.Bundeskriminalamt (eds.): Bundeskriminalstatistik. Wiesbaden: Bundeskriminalamt 2013.
2.Statistisches Bundesamt (eds.): Verurteiltenstatistik. Wiesbaden: Statistisches Bundesamt 2013.
3.Remschmidt H: Tötungs- und Gewaltdelikte junger Menschen. Ursachen, Begutachtung und Prognose. Heidelberg: Springer 2012.
4.Remschmidt H, Schmidt M, Poustka F (eds.): Multiaxiales Klassifikationsschema für psychische Störungen des Kindes- und Jugendalters nach ICD-10 der WHO, 6th edition. Bern: Huber 2012.
5.Dilling H, Mumbour W, Schmidt MH, Schulte-Markwort E (eds.): Internationale Klassifikation psychischer Störungen nach ICD-10, Forschungskriterien. Bern: Huber 1994.
6.Mattejat F, Remschmidt H: Marburger Symptom Rating (MSR). Standardisiertes Elterninterview zur Erfassung psychopathologischer Auffälligkeiten von Kindern und Jugendlichen. Bern: Huber 2010.
7.Rutter M, Quinton D: Psychiatric disorder: ecological factors and concepts of causation. In: McGurk M (ed.): Ecological factors in Human Development. Amsterdam: North Holland Publisher 1977; 173–87.
8.Hartmann K, Eberhard K: Legalprognosetest für dissoziale Jugendliche (LDJ). Göttingen: Verlag für Medizinische Psychologie im Verlag Vandenhoeck und Ruprecht 1972.
9.Sonka C, Riesner L: Junge „Mehrfach- und Intensivtäter – Implikationen für die Auswahl in polizeiliche Programme“. Forensische Psychiatrie, Psychologie, Kriminologie 2012; 6: 119–27. CrossRef
10.Wolfgang ME, Figlio RM, Sellin T: Delinquency in a birth cohort. Chicago: University of Chicago Press 1972.
11.Lynam D, Moffitt TE, Stouthamer-Loeber M: Explaining the relation between IQ and delinquency: Class, race, test motivation, school failure, or self-control? Journal of Abnormal Psychology 1993; 102: 187–96. CrossRef MEDLINE
12.Moffitt TE, Caspi A, Silva PA, Stouthamer-Loeber M: Individual differences in personality and intelligence are linked to crime. Cross-context evidence from nations, neighborhood, genders, races, and age-cohorts. In: Smith Blau Z (eds.): Current perspectives on aging and the life cycle. Delinquency and disrepute in the life course. Greenwich: JAI Press Inc. 1995; 4: 1–34.
13. Günter M, Eistetter S, Kern D: Jugendliche und heranwachsende Tötungsdelinquente. Charakteristika aus der psychiatrischen Begutachtung und späteres Rezidivrisiko. In: Duncker H, Koller M, Foerster K (eds.): Forensische Psychiatrie – Entwicklung und Perspektiven. Ulrich Venzlaff zum 85. Geburtstag. Längerich: Pabst-Science-Publishers 2006: 145–62.
14.Günter M, Eistetter S, Kern D: Jugendliche und heranwachsende Tötungsdelinquente. Charakteristika aus der psychiatrischen Begutachtung und späteres Rezidivrisiko. Forens Psychiatrie Psychother 2009; 2: 52–69.
15.Remschmidt H, Walter R: Kinderdelinquenz. Gesetzesverstöße Strafunmündiger und ihre Folgen. Heidelberg: Springer 2009.
16.Remschmidt H, Walter R: What becomes of delinquent children? Results of the Marburg Juvenile Delinquency Study. Dtsch Arztebl Int 2010; 107: 477–83. VOLLTEXT
17.Vreugdenhil C, Doreleijers TAH Vermeiren R, Wouters LFJM, van den Brink W: Psychiatric disorders in a representative sample of incarcerated boys in the Netherlands. Journal of the American Academy of Child and Adolescent Psychiatry 2004; 43: 97–104. CrossRef MEDLINE
18.Plattner B, Aebi M, Steinhausen HC, Bessler C: Psychopathologische und komorbide Störungen inhaftierter Jugendlicher in Österreich. Zeitschrift für Kinder- und Jugendpsychiatrie und Psychotherapie 2011; 39: 231–42. CrossRef MEDLINE
e1.Hosmer DW, Lemeshow S: Applied Logistic Regression (2nd edition). New York: Wiley 2000.
e2.Zwiener I, Blettner M, Hommel G: Survival analysis—part 15 of a series on evaluation of scientific publications. Dtsch Arztebl Int 2011; 108: 163–9. VOLLTEXT