Criminal Responsibility and Psychiatric Evidence in German Homicide Cases

By Dr. Julius Hagen

When mental condition becomes part of the criminal case

Questions of criminal responsibility may arise in homicide proceedings for very different reasons. A psychiatric illness may already be known. In other cases, relatives report marked changes before the offence. Heavy alcohol or drug use, an unusual sequence of events or inconsistent accounts by the defendant may also lead to a psychiatric assessment.

For defendants and their families, it is often difficult to know whether a psychiatric expert report will assist the defence or create additional risks. Both are possible.

A finding that criminal responsibility was absent or substantially diminished may exclude punishment or alter the sentencing range. At the same time, the same mental condition may form the basis for placement in a psychiatric hospital. Criminal responsibility, expert-evidence strategy and the risk of a hospital order must therefore be considered together.

How is criminal responsibility assessed in a homicide case?

Criminal responsibility is a legal concept. The psychiatric expert provides the court with the specialist foundation by describing the defendant’s mental condition, possible disorders and their effects. The court itself decides whether sections 20 or 21 of the German Criminal Code (StGB) apply.

Section 20 StGB: absence of criminal responsibility

Section 20 StGB applies where, because of a legally relevant mental condition, the defendant was incapable at the time of the offence of appreciating its wrongfulness or acting in accordance with that appreciation. The offence is then committed without criminal guilt, and punishment for that offence is excluded.

Section 21 StGB: substantially diminished criminal responsibility

If the capacity to appreciate wrongfulness or to control conduct was not eliminated but substantially diminished, section 21 StGB may apply. The defendant remains criminally responsible, but the sentencing range may be reduced. In a murder case, this can materially affect the sentence.

A diagnosis alone does not answer the legal question

A diagnosis of schizophrenia, a personality disorder or an addiction does not by itself establish section 20 or section 21 StGB. A mental disorder may be severe without explaining the offence. A person with a psychiatric illness may also act for motives unrelated to that illness.

The defendant’s condition at the time of the offence must be reconstructed retrospectively

The expert will often examine the defendant weeks or months after the event. The assessment nevertheless concerns the time of the offence. This retrospective reconstruction does not depend on the interview alone.

Not every unusual feature described after the event is reliable evidence of a mental disorder. Following a serious offence, earlier behaviour is often reinterpreted. The assessment must therefore distinguish contemporaneously documented observations from later evaluations and mere assumptions.

Capacity to appreciate wrongfulness and capacity to control conduct

Capacity to appreciate wrongfulness

This concerns whether the defendant could appreciate the wrongfulness of the specific act. Abstract knowledge that killing is prohibited is not enough. The issue is whether the defendant could correctly perceive the situation and understand the significance of the conduct.

Capacity to control conduct

This concerns the ability to align conduct with an existing appreciation of wrongfulness. A person may understand that the act is wrong yet, because of a severe mental condition, be substantially impaired in the ability to refrain from it.

Planning, adaptation to external circumstances, interruptions or concealment may indicate preserved mental functions. They are not conclusive counterevidence. Conversely, a disorganised or particularly violent course of events does not by itself prove loss of control.

The factual basis of the psychiatric report

A psychiatric report rests on factual assumptions about the background, the course of the offence and motive. Under German law, these are the factual premises of the expert opinion. In homicide proceedings, the factual picture is often provisional at an early stage.

If the expert initially assumes a spontaneous escalation, the assessment of affect and control may differ from an assessment based on prolonged preparation. If witness evidence, digital traces or forensic findings later alter the factual picture, the expert conclusions must be reconsidered.

Common psychiatric scenarios in homicide cases

Psychotic disorders

In an acute psychosis, the central issue may be whether the defendant misperceived reality because of the illness. The relevant symptoms must have existed at the time of the offence and must have related to the victim or the specific situation.

Personality disorders

The severity of the disorder is central. Sensitivity to rejection, impulsivity, jealousy or aggressive conflict patterns do not by themselves establish section 20 or 21 StGB. The seriousness of the offence must not be equated with the severity of the disorder.

Extreme affective states

Anger, fear of loss, jealousy or humiliation may trigger a killing without substantially diminishing criminal responsibility. The label “crime of passion” initially describes emotional escalation only. It becomes legally relevant only where the intensity and effects clearly exceed the normal range of severe emotional arousal.

Alcohol, drugs and medication

Even a high blood-alcohol concentration requires an overall assessment. Toxicology must be considered together with the drinking history, tolerance, visible impairment and the complexity of the conduct. Memory gaps do not by themselves answer the question of criminal responsibility.

A forensic psychiatric examination is not therapy

The psychiatric expert will often seek to examine the defendant personally. The interview may cover medical history, personal development, substance use and the alleged offence.

The defendant is not required to incriminate himself or herself. At the same time, the expert may depend on the defendant’s account when assessing internal experiences. Whether and to what extent the defendant participates is therefore a strategic decision.

The expert is not acting as a treating physician. The examination is part of the evidentiary process. Statements may be reproduced in the written report and discussed at trial. An interview may be indispensable, but it should be prepared and coordinated with the wider defence strategy.

When an independent defence expert may be useful

The defence may instruct an independent forensic psychiatrist or specialist adviser. This does not necessarily require a complete counter-report. Often the first task is to review the court-appointed expert’s work.

Sentencing consequences and the risk of psychiatric placement

Absence of criminal responsibility under section 20 StGB

If the capacity to appreciate wrongfulness or to control conduct was eliminated because of a legally relevant condition, punishment for the specific offence is excluded. This does not necessarily mean that the defendant will be released.

Diminished criminal responsibility under section 21 StGB

Where criminal responsibility was substantially diminished, the defendant remains responsible but the sentencing range may be reduced. In a murder case, this may permit a determinate sentence instead of mandatory life imprisonment.

Criminal responsibility and section 63 StGB require one defence strategy

Psychiatric findings may assist the defence while creating a new risk. Mental illness alone is not sufficient for placement in a psychiatric hospital under section 63 StGB. The court must also establish a connection between the condition and the offence and a risk of further serious unlawful acts arising from that condition.

The risk assessment concerns the future and may rely on the course of the illness, personal history, the index offence, treatment options and social support. The defence must therefore assess the possible hospital order from the outset, not merely the prospect of a reduced sentence.

Provisional psychiatric placement during the proceedings

Psychiatric placement may become relevant before judgment. Under section 126a of the German Code of Criminal Procedure (StPO), a defendant may be provisionally placed in a psychiatric hospital where there are strong reasons to expect a later hospital order and public safety requires provisional placement.

Our approach to psychiatric evidence in homicide cases

In homicide proceedings, psychiatric assessment is closely connected with the rest of the evidence. The expert can assess the defendant’s condition only against an assumed factual account. Conversely, the mental condition may explain why conduct or statements should be interpreted differently from their initial appearance.

We act throughout Germany in homicide cases, during the investigation, in pre-trial detention, after indictment and before the specialist homicide chamber of a German Regional Court.