Nullity of Custody: No Effect on Prior Acts – What to Do?

Imagine the scene: you are a homeowner in Gemenos, returning home after a heavy dinner, and you are stopped by the police. The alcohol screening is positive. You are placed in police custody. But then your lawyer discovers an irregularity in the procedure: your rights were not properly notified at the start of custody. Good news? Not necessarily. The Court of Cassation has ruled: even if the custody is annulled, acts carried out before, such as the screening, remain valid. A crucial question then arises: what can be challenged and how can you defend yourself? This 1999 decision, still relevant today, sets limits that directly affect you, whether you are a motorist, a landlord, or a property professional. Analysis.

The facts: a story like many others

Mrs. Y., a resident of Septèmes-les-Vallons, is stopped while driving her vehicle during a road check. The gendarmes conduct an alcohol screening, then a second verification test. Result: her alcohol level exceeds the legal limit. She is placed in police custody. The report states that her rights were notified at the start of the measure. However, during her trial, her lawyer raises an exception of nullity (i.e., a request for annulment) of the custody, arguing that the notification was not made immediately. The Court of Appeal rejects this request, confirming Mrs. Y.'s conviction for drink-driving. Dissatisfied, she appeals to the Court of Cassation, arguing that the nullity of the custody should entail that of prior acts. The Court of Cassation, in its judgment of 9 June 1999, dismisses her appeal: the nullity of the custody does not affect the screening and verification reports, which were regularly established before the placement in custody. In short, even if the custody was irregular, the evidence gathered beforehand remains valid. A decision that set a precedent and continues to apply.

The reasoning of the court — explained

To understand this decision, it is necessary to distinguish between acts prior to custody and those subsequent to it. The Court of Cassation relies on the principle of independence of procedural acts: an irregularity that occurs after an act does not affect the validity of that act if it was carried out correctly. In this case, the alcohol screening and verification reports were drawn up before placement in custody and complied with the provisions of the Code of Criminal Procedure (Articles 56-1 and following). Consequently, their nullity cannot be pronounced. The Court therefore rejects the ground of appeal (the argument raised by Mrs. Y.) as inoperative, i.e., without effect on the outcome of the dispute. It also recalls that the report of notification of rights, signed by the person concerned, established that the notification had taken place at the start of custody. In other words, the Court considered that the facts were regular on the merits, and the criticism was limited to procedural aspects without impact. This reasoning has been consistent since: the nullity of custody does not have retroactive effect on prior acts regularly performed. However, note that if the irregularity had concerned the conditions of the screening itself (for example, a non-approved device), the decision could have been different. What few people know is that this case law also applies to other areas, such as searches or seizures, provided the prior act is autonomous.

What this means for you — concretely

For motorists, this decision means that challenging custody is not enough to annul evidence of alcohol or drugs. If you are checked and the screening is positive, you must imperatively verify that the test itself was carried out in accordance with the rules (compliance with time limits, certified device, etc.). undefined, I have come across cases where clients in Septèmes-les-Vallons tried to have the entire report annulled by invoking nullity of custody, without success. For landlords, this decision has a more indirect scope: it illustrates the principle of autonomy of acts. For example, if you sign a lease and the tenant later challenges a procedural act in a dispute (such as a notice to pay), the act itself remains valid if it was regular at the time of issue. Concretely, if you are a homeowner in Gemenos and wish to evict a tenant for non-payment, an irregularity in the subsequent procedure (e.g., a poorly notified summons) will not annul the initial notice to pay, which serves as the basis for the action. Therefore, you must ensure the regularity of each act, but also know that prior acts are protected. For buyers, during a property sale, if a subsequent act after the promise to sell is annulled (e.g., the compromise for defect of consent), the promise itself may remain valid if it was regularly concluded. This reinforces the legal security of transactions. Conversely, if you are a tenant, bear in mind that your remedies must be based on defects specific to the contested act, and not on subsequent irregularities.

Four tips to avoid this type of dispute

• Keep all screening and verification reports: in case of a check, demand a copy of the results and verify the mandatory details (date, time, officer's name, type of device). This will allow you to challenge the substance if necessary.
• Do not sign a report without reading it carefully: any error or omission in the notification of your rights must be reported immediately and noted in the report. Your signature acknowledges the facts, but not agreement with their regularity.
• Consult a lawyer from the start of the procedure: within the first hours after a check, a lawyer can verify the regularity of the screening and custody. In Gemenos, it is possible to contact a legal advisor quickly.
• Distinguish between nullities: not all nullities are equal. A nullity of custody does not affect prior acts, but a nullity of the screening itself (for example, due to lack of approval of the breathalyser) can lead to the annulment of the entire procedure.

Further reading: related case law and developments

This decision is part of a consistent line of the Court of Cassation. For example, the judgment of 20 February 2001 (No. 00-84.127) confirmed that the nullity of a search carried out without the person's consent does not affect prior findings made during a flagrante delicto investigation. Similarly, in matters of custody, the Criminal Chamber recalled in a judgment of 10 January 2017 (No. 16-80.603) that only acts subsequent to the irregularity are liable to be annulled. The trend is therefore clear: judges favour the stability of regularly obtained evidence, even if it limits the scope of procedural nullities. This means that in the future, lawyers will have to focus their challenges on the acts themselves, rather than on subsequent defects. For individuals, it is a reminder that the regularity of each step is crucial, but the chronology of the acts plays a protective role.

Frequently asked questions

• What should I do if I think my alcohol screening is irregular? Gather evidence immediately: request a copy of the report, check the approval date of the device, and contact a specialised lawyer to apply for an expert determination on an urgent basis.
• Can I challenge a fine for alcohol if the custody was null? No, not on that ground alone. You must prove that the screening itself is tainted by irregularity (e.g., lack of prior verification).
• What is the time limit to challenge custody? The nullity must be raised before any defence on the merits, generally at the trial hearing. After that time, it is inadmissible.
• Does this decision apply to drug checks? Yes, the same reasoning was applied by the Court of Cassation in a judgment of 14 January 2020 (No. 19-80.134): saliva tests prior to custody remain valid.
• What should I do if I am a victim of a procedural error? Consult a lawyer without delay. An initial review of your file can determine whether the prior acts are regular or not.

Are you in a similar situation? A first 30-minute consultation with Maître Zakine (€45) can save you months of proceedings — and often much more. Book an appointment →