Term and Definition: Nachtrunk (post-offense drinking)
The term Nachtrunk refers, in the legal context, to the consumption of alcohol or other intoxicating substances after the commission of a criminal offense. This term is particularly relevant in criminal law when determining the culpability of a suspect at the time of the offense, provided that alcohol or similar substances were consumed after the crime.
The precise evaluation of Nachtrunk has a significant impact on assessing criminal responsibility, especially in cases where diminished or eliminated culpability (§§ 20, 21 StGB) or evidentiary challenges regarding blood alcohol content at the time of the offense play a role.
Relevance in Criminal Law
Nachtrunk and Culpability
The determination of culpability in criminal law depends on the condition of the offender at the time of the offense. Nachtrunk presents challenges because a subsequent measurement of blood alcohol concentration may distort the actual BAC at the time of the offense. To evaluate the post-offense consumption of alcohol—the so-called Nachtrunk—accurately from a criminological and judicial perspective, law enforcement authorities comprehensively examine and document the consumption after the commission of the offense.
Significance in Driving Incapacity
Nachtrunk is of particular importance in traffic law when assessing alcohol- and drug-related offenses in road traffic (§§ 316, 315c StGB). The key point is to carry out the most accurate possible retrograde calculation of the alcohol level at the time of the offense. Here, alcohol consumed between the time of the incident and the official determination is calculated out or differentiated in the legal assessment.
Burden of Proof, Evidence, and Evaluation of Nachtrunk
Requirements for Credibility
An assertion of Nachtrunk must be understandable, specific, and plausible. The suspect bears the burden of presentation; however, law enforcement authorities are not obliged to accept the claim at face value but must critically examine whether the statements by the accused are consistent with established facts, witness statements, and forensic opinions.
Information on the type, amount, timing, and circumstances of the Nachtrunk are required. Authorities investigate whether there was an opportunity, possibility, and motivation for a Nachtrunk. If understandable details are missing or doubts exist regarding the account, this negatively affects the accused (principle: “in dubio pro reo” applies with limitations).
Retrograde Calculation of Blood Alcohol Level
To reconstruct the blood alcohol concentration at the time of the offense, retrograde calculation methods are used. These take into account:
- Amounts of alcohol consumed
- Body weight
- Interval between the offense and blood sample
- Absorption delay and absorption phase
According to the widely recognized Widmark formula and the guidelines of the Society for Toxicological and Forensic Chemistry (GTFCh) and consistent case law (e.g. BGHSt 46, 358), a precise calculation is carried out. If Nachtrunk is credibly demonstrated, the corresponding amount of alcohol must be deducted.
Case Law on Nachtrunk
Key Decisions
The highest courts have established principles for the assessment of Nachtrunk:
- BGH, Judgment of 19.01.2001, Case No. 2 StR 508/00: The mere assertion of Nachtrunk by the accused is insufficient. Concrete and plausible information is required.
- OLG Hamm, Decision of 31.03.2008, Case No. 2 Ss OWi 203/08: Nachtrunk must be taken into account if doubts about its inaccuracy cannot be dispelled. Due to the principle of doubt, where the Nachtrunk hypothesis can seriously be considered, the decision must favor the defendant in case of doubt.
Nachtrunk in Regulatory Offenses
Nachtrunk also applies in administrative offense law, particularly in alcohol-related traffic offenses (§ 24a StVG). The affected individual has the opportunity to invoke Nachtrunk as an exculpatory factor. The regulatory authority must then individually verify and assess whether the charge can be maintained.
Consequences and Legal Effects Upon Proof of Nachtrunk
Complete Exclusion of the Act Due to Intoxication
If it is established that alcohol consumption occurred entirely after the offense, proof of the crime cannot be established. This may lead to acquittal.
Partial Proof of BAC at the Time of the Offense
If only part of the consumption is proven, the remaining BAC is calculated based solely on the alcohol consumed before the crime. Criminal or culpable influence of alcohol while driving is then to be judged only to this extent.
Nachtrunk: Delineation and Practical Significance
Distinction from Consumption at the Time of the Offense
Nachtrunk differs from conventional consumption at the time of the offense in that it serves solely to conceal the actual condition at the time of the offense. Determining Nachtrunk can therefore result in partial or complete dismissal of criminal or administrative consequences.
Practical Significance
Investigating Nachtrunk presents significant evidentiary challenges for both investigative authorities and courts. It is standard practice to secure a blood sample as soon as possible after an accident or suspicion of a crime and to record whether alcohol was consumed after the incident.
Literature and Sources
For further reading, relevant commentaries and manuals on criminal and traffic law are recommended, for example:
- Fischer, Criminal Code (Commentary on §§ 20, 21 StGB)
- Burmann/Heß/Jahnke/Janker, Road Traffic Law
- Various case law databases
Summary
Nachtrunk is a complex legal term that is of considerable significance in the context of assessing alcohol intoxication at the time of the offense. The assessment is based on specific information, forensic evidence, and, in cases of doubt, application of the principle of retrograde calculation. Proof of Nachtrunk can have a decisive impact on culpability, sentencing, and criminal responsibility.
Frequently Asked Questions
Who bears the burden of proof for an alleged Nachtrunk under road traffic law?
In the context of criminal and administrative offense law in road traffic, the burden of proof for an alleged Nachtrunk generally lies with the affected individual or the accused. This means that a person who claims to have consumed most of the alcohol only after driving under the influence is obliged to make this assertion plausible. The court must be convinced by the account—although mathematical precision is not required, a plausible, coherent, and, if necessary, supported presentation by witnesses or circumstantial evidence is expected. Often, an expert opinion is sought as part of a “Nachtrunk defense” to retroactively calculate the blood alcohol value. The court will then determine in each individual case whether the presentation is sufficiently substantiated or merely a defensive assertion.
What role does Nachtrunk play in sentencing or administrative fines?
A plausibly proven Nachtrunk can have significant impact on sentencing or a verdict in proceedings for drunk driving (§ 316 StGB) or a corresponding administrative offense. If evidence for Nachtrunk is successful, it may be necessary to calculate the relevant blood alcohol level for the time of the offense, not the value at the time of blood sampling or breath analysis. This may result in falling below legal thresholds (such as the 0.5 per mille limit), which can be decisive for sanctions. If the blood alcohol level drops below the limit due to consideration of Nachtrunk, criminal or administrative liability may be avoided.
How do courts assess the credibility of a Nachtrunk claim?
Courts view claims of Nachtrunk with particular skepticism, as it is a common defensive assertion in administrative and criminal proceedings. They therefore examine whether the Nachtrunk presentation is coherent, consistent, and supported by evidence or witness statements. Indicators such as the type and amount of alcohol allegedly consumed after driving, the exact timing and circumstances of consumption, and the reaction to police officers (e.g., immediate voluntary disclosure) are considered in the assessment. If there is a lack of compelling evidence or inconsistencies are present, Nachtrunk is usually considered implausible and disregarded.
What are typical pieces of evidence in a Nachtrunk defense?
The most typical and admissible evidence for Nachtrunk consists primarily of testimony from persons who observed the alcohol consumption after the drive. In addition, receipts or video recordings showing both the purchase and consumption of alcohol at the location may be presented. Furthermore, a forensic medical expert opinion may be used to retroactively calculate blood alcohol levels. It is important that all circumstances making Nachtrunk plausible are fully and thoroughly explained.
What is the significance of police cautions in the context of Nachtrunk?
The police caution of the accused pursuant to § 163a para. 4 StPO or § 46 OWiG is relevant to the extent that the accused has the right to remain silent. If the accused voluntarily mentions Nachtrunk before being cautioned—or only refers to it later after legal advice—this may affect the credibility assessment of the Nachtrunk claim. Additionally, police should always document the time sequence between the end of driving, the detected alcohol consumption, and blood sampling, to ensure later evaluation during legal proceedings.
Until when can Nachtrunk be asserted?
Nachtrunk can generally be asserted up to the conclusion of the court hearing in a criminal or administrative offense proceeding. However, credibility is negatively affected if the claim is made only late in the process, such as during the main hearing. Early and consistent statements, on the other hand, significantly improve the chances of the claim’s success.
Can alcohol offenses be entirely dismissed if Nachtrunk is successfully proven?
If Nachtrunk is sufficiently proven and the retroactively calculated blood alcohol level is below the statutory thresholds (e.g., 0.5 ‰ or 1.1 ‰), sanctions may be waived. However, if, despite the Nachtrunk claim, there is at least relative driving incapacity or if alcohol-related impairment is documented, even a valid Nachtrunk assertion will not necessarily lead to complete immunity from punishment. In such cases, all circumstances of the individual case are decisive.
What are the effects of Nachtrunk on measures relating to driving licenses?
Even if criminal liability is negated due to Nachtrunk in a specific case, the licensing authority may still take measures under driving license law based on the findings made during criminal or administrative proceedings. This particularly concerns the order for a medical-psychological assessment (MPU) if doubts about fitness to drive persist or alcohol abuse is suspected. The assessment is based on an overall evaluation of whether the Nachtrunk account is also sufficient for evaluating fitness to drive.
