Grounds for detention.

The basic preconditions of pre-trial detention

In Austria, pre-trial detention may be ordered only where two requirements are met simultaneously: a strong suspicion (dringender Tatverdacht) of an offence punishable by a criminal court, and at least one ground for detention under Section 173(2) StPO (Strafprozessordnung / Code of Criminal Procedure). If either is missing, the detention is unlawful. The strong suspicion requires a significantly higher probability than mere initial suspicion: on the state of the file, it must be more likely than not that the accused committed the offence. The bare possibility is not enough, the court must weigh incriminating against exculpatory circumstances and set its assessment out in the reasoning for detention.

On top of this comes the requirement of proportionality under Section 5 StPO. Pre-trial detention is ultima ratio: it is permitted only where the purpose cannot equally be achieved by a less intrusive measure (gelinderes Mittel), a directive, bail (Kaution) or an electronic ankle tag. Its duration must also not be out of proportion to the sentence to be expected. Proportionality has to be examined afresh at every detention decision, at first order, at every detention review hearing and at every decision on continuation. The longer detention lasts, the stricter the test.

Section 173(2) StPO, the four grounds for detention

The statute lists the grounds exhaustively: first, risk of flight (Fluchtgefahr); second, risk of collusion (Verdunkelungsgefahr); third, risk of repeated offending (Tatbegehungsgefahr); fourth, risk of execution (Ausführungsgefahr). A single ground, established concretely, suffices, conversely, the fall-away of one ground that has until now carried the detention may justify release, provided the remaining grounds do not stand on their own. Every ground must be reasoned in relation to the offence and on the individual facts; a blanket reasoning based on the abstract seriousness of the allegation is not enough.

The four grounds differ clearly in structure. Risk of flight and risk of collusion safeguard the ongoing proceedings: they prevent the accused from evading the authorities or damaging the evidence. Risk of repeated offending and risk of execution, by contrast, serve the preventive protection of the public, or of specific persons, from further offences. Once the system is understood, it quickly becomes visible which ground carries weight in which phase of the proceedings, and where the defence can make a concrete start.

Risk of flight (Section 173(2)(1) StPO)

Risk of flight exists where specific facts suggest that the accused will evade the criminal proceedings by fleeing or going into hiding. Classic indicators are a concrete foreign nexus (foreign citizenship, residence or assets abroad), the absence of family and professional ties in Austria, and the specific prospect of a heavy custodial sentence, the heavier the expected sentence, the greater the presumed incentive to flee.

Sentence expectation alone, however, never carries the ground. The Supreme Court (Oberster Gerichtshof) consistently requires objective indications to be added: preparations for flight, contacts abroad, means and routes for flight. Those firmly anchored at the place of proceedings, with family, employment, home ownership, can rebut the presumption. Typical less intrusive measures are the deposit of the passport, an obligation to report at a police station, or bail. A properly documented social environment is the most important lever of the defence here.

In practice, the defence assembles a catalogue of evidence: residence registration, tenancy contract or land register extract, employment contract with a recent payslip, school confirmations for the children, evidence that relatives depend on care. The more densely the network of domestic ties is documented, the harder it becomes to reason a risk of flight. Where the financial circumstances allow it, bail (Kaution) can be agreed with the court as to amount and form.

Risk of collusion (Section 173(2)(2) StPO)

Risk of collusion means the danger that the accused will destroy, alter or hide away evidence, influence witnesses or co-accused, or remove traces. It is the typical ground for detention in the early investigative phase, while the file is still thin, witnesses not yet interviewed and electronic evidence not yet secured.

For that very reason, risk of collusion carries less weight as the proceedings progress. Once witnesses have been interviewed, data carriers examined and searches completed, there is simply nothing left to conceal. The defence typically starts here: it demonstrates that the investigatively relevant evidence has already been secured and applies for release on the basis that the purpose of detention has been achieved. Concrete undertakings, handing over data carriers, renouncing contact with named witnesses, can likewise suffice as a less intrusive measure.

The personnel constellation also matters: risk of collusion presupposes that the accused actually has the means to exert influence. If the only incriminating witness is themselves in custody or lives in an entirely separate sphere, the real possibility of influence is often missing. Equally important: risk of collusion justifies detention only for as long as it genuinely exists, where the court simply carries it over in a later review hearing without the evidentiary situation having changed, that is a classic point of attack in the detention appeal (Haftbeschwerde).

Risk of repeated offending (Section 173(2)(3) StPO)

Risk of repeated offending exists where there is reason to fear that the accused, if at liberty, will commit further criminal offences with more than merely trivial consequences that are directed against the same legally protected interest or stem from the same harmful inclination. Typical fields of application are relevant prior convictions, serial offending in property or drug crime, and violent offences in unstable social circumstances.

The ground requires a concrete prognosis, not a blanket assumption. Relevant prior convictions alone are not enough; the court must set out why, in the present situation, a risk of repetition is tenable. The defence works here with evidence of changed circumstances of life: a therapy placement, withdrawal treatment, a stable job, integration into a family. In many cases the risk of repeated offending can be absorbed by directives and probation (Bewährungshilfe) as a less intrusive measure.

The temporal dimension weighs heavily: a prior conviction from 2015 counts differently for today's prognosis than a relevant conviction from the previous year. The nature of the current allegation counts too, a one-off, situational incident supports a prognosis of further offences less readily than a documented series. Where the defence presents a credible forward-looking perspective, a concrete therapy placement, a confirmation of employment and a stable domestic environment, the ground often loses its load-bearing capacity. The electronic ankle tag (Fußfessel) is a further option which, in cases of addiction combined with a therapy directive, can become an effective instrument of control.

Risk of execution (Section 173(2)(4) StPO)

Risk of execution is the danger that the accused will actually carry out an offence with serious consequences that they have concretely announced or threatened. The ground therefore presupposes a specific, already-indicated offence, typically a serious threat against a concrete person. In practice, risk of execution is rarely the load-bearing ground; it usually appears alongside other grounds and serves as a safety net in cases where threats are documented.

Where risk of execution is argued, the concreteness of the announced offence is decisive: whom does the accused threaten? With what act? How credible is the announcement on the state of the file? General outbursts of anger, or distant threats uttered in a heated moment, regularly do not justify detention. Possible less intrusive measures include a contact ban in respect of the person threatened, a directive to undergo therapeutic work-through, or electronically monitored house arrest.

Concreteness and individual case focus

Running through all four grounds is the same requirement: the reasoning must be concrete, related to the offence and individually tailored. Sentences such as "given the seriousness of the allegation, risk of flight is given" or "in drug offences there is typically a risk of repeated offending" are blanket reasonings and, as a rule, do not survive a detention appeal. The Supreme Court demands engagement with the personal circumstances, with the concrete facts of the offence and with possible less intrusive measures.

An important strategic point follows: if the defence succeeds in unsettling even one of the grounds hitherto assumed, that may support release, provided the remaining grounds do not stand on their own. More often, the path ends not in full release but in a less intrusive measure: bail, directives, ankle tag. That is a full success, too. In practice, both lines are worth preparing in parallel, the detention appeal attacks the reasoning on the merits, while the application for a less intrusive measure offers the court a viable way out it can choose without losing face.

What our firm does

We examine the detention order word by word, put every single ground to the test and work out concrete counter-evidence, from proof of residence through confirmation of therapy to arranging bail. For the overall proceedings see our pre-trial detention practice; the defence in the main proceedings runs in parallel through our sister site strafsachen.at.