Victims

The Institute of Forensic Medicine autopsied 106 homicide victims between 2012 and 2019. The victims were 51.9% (n = 55) male and 48.1% (n = 51) female. On average, male victims were 48.2 ± 19.4 years (median 47 years), and female victims 48.5 ± 22 years (median 44 years) old (Fig. 1).

Fig. 1

Age distribution of the victims

The victims were predominantly German (64.2%; n = 68), 34.9% (n = 37) were non-German citizens, and in 0.9% (n = 1) citizenship was unknown. Male victims were more often non-German than female victims (male 40.0%, n = 22; female 29.4%, n = 15), but the difference was not statistically significant.

Perpetrators

The perpetrators were frequently male (84.0%) and between 30 and 49 years old (42.5%). Female perpetrators were less frequent (7.5%). In 8.5% the perpetrators could not be identified.

The perpetrators were predominantly German citizens (56.6%), 34.0% were non-German, one perpetrator (0.9%) held both German and non-German citizenship, and 8.5% of the perpetrators remained unidentified. Among male victims, the perpetrators were slightly more likely to be non-German than among female victims (male 38.2%; female 31.4%). The difference regarding the gender of the victims was not statistically significant.

In 37.3% of the female and 32.7% of the male victims, mental illnesses of the perpetrators were documented in the files. Difference regarding gender of the victims was not statistically significant. Addictive diseases of the perpetrators were reported statistically significant more often when the victim was male (49.1%) than female (27.5%), (p = 0.017) (Table 2).

Table 2 Statistically significant differences in female and male victims

In 39.2% of the female victims and 52.7% of the male victims, the perpetrators had prior convictions; however, in 24.5% of these cases, this information was absent. Differences regarding the gender of the victims were statistically not significant.

Previous assaults, verbal threats or stalking

In 55.7% of the total collective, a previous assault, verbal threat, or stalking was registered towards the victims. These events occurred more frequently among male (61.8%, n = 34) than female (49.0%, n = 25) victims, although the difference was not statistically significant.

Perpetrator-victim relationship

Female victims (96.1%, n = 49) were statistically significantly more likely to be killed by perpetrators they knew before than male victims (80.0%, n = 44), (p = 0.039). New acquaintances immediately before the crime were assigned to the category “unknown to each other”. In 3.8% (n = 4) of the total collective, perpetrator and victim were unknown to each other.

In the total collective, the victims were killed in 34.0% each by acquaintances/ friends and intimate partners. Gender separated analysis showed, that male victims were most often killed by acquaintances/ friends (male 54.5%, n = 30) and female victims by intimate partners (62.7%, n = 32). In 15.1% (n = 16) of the total collective, the victims were killed by family members (without intimate partners), the gender distribution in these relationships was nearly equal (male 14.5%, n = 8; female 15.7%, n = 8). In the majority of these cases (n = 11), the perpetrators were adult (step)children (Table 2; Fig. 2).

Fig. 2

Perpetrator-victim relationships

To analyze statistically relevant differences in the perpetrator-victim relationships, the data were categorized into two groups: intimate partners and other acquaintances or relatives. The evaluation revealed that women were significantly more often killed by intimate partners, and men significantly more often by other acquaintances or relatives (p < 0,001).

Crime scene and time

Female victims (76.5%, n = 39) were killed twice as often as male victims (36.4%, n = 20) in their own home (including rarely own office) and male victims (63.6%, n = 35) nearly three times more likely (23.5%, n = 12) at other crime scenes (e.g. public places, a stranger´s home, forest or field). Difference regarding gender was significant (p < 0,001) (Table 2; Fig. 3).

Fig. 3

Both male (54.5%, n = 30) and female victims (55.0%, n = 28) were killed primarily in the evening and at night (6 pm to 6 am).

Types of violence and instruments of crime

Both male and female victims most frequently died from stabbing and cutting injuries, with men more likely to die from these injuries than women (male 52.7%, n = 29; female 39.2%, n = 20). Female victims were slightly more likely to suffer from forcible asphyxiation (male 14.5%, n = 8; female 21.6%, n = 11) and blunt force trauma (male 12.7%, n = 7; female 17.6%, n = 9). Gunshot injuries were more likely to occur to male than female victims (male 18.2%, n = 10; female 11.8%, n = 6) (Fig. 4).

Fig. 4

Type of violence causing death

Including injuries that were not the cause of death, in 67.9% (n = 72) of the total collective stabbing or shooting injuries were present. One to five injuries were found in 39.6% (n = 42) and six to fifty injuries in 28.3% (n = 30) of these cases. Male victims were significantly more likely to have one to five stabbing/ shooting injuries (male 52.7%, n = 29; female 25.5%, n = 13), while females were significantly more likely to have a variety (six to fifty) of these injuries (male 23.6%, n = 13; female 33.3%, n = 17); (p = 0.029). In nine cases with numerous injuries, partial or total exemption from criminal responsibility was assumed due to mental illness of the perpetrator.

Instruments of crime were used in 85.8% of the cases, gender-separated analysis revealed no significant differences (female 84.3%, n = 43; male 87.3%, n = 48). The most frequently used instruments of crime were knives (45.3%, n = 48) and firearms (15.1%, n = 16), particularly among male victims (Fig. 5).

Fig. 5Substance influence of the victims

The criminal history indicates that 41.5% of the victims were influenced by alcohol, drugs, or medication at the time of the crime. In male victims the rate was significantly higher (56.4%, n = 31) than in female victims (25.5%, n = 13), (p = 0.001). The measure of blood alcohol concentration was positive in 40.0% (n = 22) of the male and 17.6% (n = 9) of the female victims (p = 0.015). In addition, toxicological analysis revealed substance influence by drugs and/or medication in 21.8% (n = 12) of the male and 15.7% (n = 8) of the female victims, although the difference was statistically not significant.

Substance influence of the perpetrators

The case files revealed that alcohol, drugs, or medication influenced the perpetrators in 43.4% of the cases at the time of the crime. In these cases, the victims were more often male than female (49.1%, n = 27 vs. 37.3%; n = 19), but the difference was not statistically significant. In 32.7% (n = 18) of the male and 21.6% (n = 11) of the female victims, the blood alcohol measure of the perpetrators revealed positive results (p = 0.019) (Table 2). A toxicological analysis of the perpetrators revealed the influence of drugs or medication in 25.5% (n = 14) of the male victims and 19.6% (n = 10) of the female victims, but the difference was not statistically significant.

Suicide of the perpetrator

The analysis revealed that 8.5% (n = 9) of the perpetrators, who were exclusively men, committed suicide immediately after the crime. These were almost exclusively partnership offenses with female victims (15.7%, n = 8).

Exemption from criminal responsibility

In 13.2% (n = 14), a forensic psychiatric expert opinion determined a partial exemption from criminal responsibility (Sect. 21 StGB) and in 15.1% (n = 16) a total exemption from criminal responsibility (Sect. 20 StGB). In 24.5% (n = 26), no information was available. There were no significant differences regarding the gender of the victims.

Conviction

24.5% (n = 26) of the final verdicts were ruled as manslaughter by the court, and 27.4% (n = 29) were ruled as murder. In 5.7% (n = 6), the court ruled bodily harm resulting in death. Robbery resulting in death (1.9%; n = 2) and intentional intoxication (cases in which the offender intentionally intoxicates themselve so that their criminal responsibility is limited or excluded at the time of the offense, section 323a StGB) (0.9%; n = 1) were rare verdicts, just in cases of male victims.

In 22.6% (n = 24), criminal cases were dismissed due to suicide of the perpetrator, unidentified or fugitive perpetrators, and total exemption from criminal responsibility. In 13.2% (n = 14) of the cases, murder, manslaughter, or bodily harm resulting in death was determined due to total or partial exemption from criminal responsibility, and placement of the perpetrators in a psychiatric hospital was ordered. In 3.8% (n = 4), criminal proceedings were still ongoing. There were no significant differences in the court decisions regarding male and female victims (Fig. 6).

Fig. 6

Conviction of the perpetrators