Stratagem in Police Custody: Unfair Evidence Inadmissible

Imagine: you own a flat in Talence, and your tenant accuses you of failing to carry out repairs. You are summoned to the police station in Bordeaux. You are placed in police custody in a cell adjoining that of the tenant, and the room is bugged without your knowledge. You talk, you lose your temper, you confess… but these confessions were induced. Are they valid? The Court of Cassation addressed this question in a judgment of 7 January 2014 (No. 13-85.246), which concerns a criminal case, but whose principle — the fairness of evidence — applies to all disputes, including property law.

In short, the high court censured a police procedure described as a "stratagem": placing two suspects in neighbouring cells, bugging the premises, and hoping they would incriminate each other. For the judges, this method taints the search for evidence and infringes the right to a fair trial. In other words, evidence obtained by trickery is not admissible, even if it is factually accurate.

But what exactly does this change for you, as a property owner in Bordeaux or a property professional? This decision reinforces the requirement of fairness in all proceedings, whether criminal or civil. It protects you if, for example, your landlord or neighbour seeks to obtain evidence by unfair means (clandestine recording, provocation, etc.). Let us analyse this case and its practical implications together.

The Facts: A Story Like Many Others

The case concerns a man, let us call him Mr. X, suspected of involvement in an armed robbery at a jewellery shop in Bordeaux. Placed in police custody, he is taken to a cell at the gendarmerie. What Mr. X does not know is that the cell is bugged with the authorisation of an investigating judge, and that his alleged accomplice (let us call him Y) is in the adjoining cell. The investigators deliberately set up this device: they want to capture their conversations, hoping the two men will speak freely, believing they are alone.

The stratagem works: Mr. X and Y talk through the partition, and Mr. X makes statements that incriminate him. These remarks are recorded and transcribed. Before the judge, Mr. X challenges the validity of this evidence, arguing that he was trapped. But the Court of Appeal upholds the procedure, considering that the bugging was authorised and that the rights of the defence were respected. The case goes up to the Court of Cassation.

What is striking about this case is the parallel with everyday situations. undefined, I have come across cases where a Bordeaux landlord had installed a hidden camera in the building hallway to film the comings and goings of his tenant, or a neighbour in Talence who secretly recorded the conversations of a co-owner. The question is always the same: is evidence obtained in secret admissible? The answer is no, if it results from an unfair procedure.

The Reasoning of the Court — Analysed

The Court of Cassation quashed the Court of Appeal's judgment. Its reasoning rests on two pillars: the right to a fair trial (Article 6 of the European Convention on Human Rights) and the principle of fairness of evidence. This principle, although no French text expressly formulates it, is derived from case law: evidence cannot be obtained by fraudulent or unfair means.

The judges of the Quai de l'Horloge considered that the combination of three measures constituted a "stratagem": 1) placement in police custody, 2) placement in adjoining cells, and 3) bugging of the premises. The sole purpose was to induce Mr. X to incriminate himself. It does not matter that the bugging was authorised by a judge: the procedure as a whole is unfair.

However, note: the Court does not challenge bugging itself, which can be lawful in the context of an investigation. What it condemns is the stratagem that "taints the search for evidence". In other words, the investigators actively induced the confessions, instead of collecting existing evidence. It is the difference between passive eavesdropping and a set-up.

What few people know is that this principle of fairness also applies in civil disputes, particularly in property law. For example, an audio recording made without the tenant's knowledge to prove noise nuisance may be ruled inadmissible. The Court of Cassation has reaffirmed this in other judgments: fairness is a general principle.

What This Changes for You — Practically

For the landlord: You cannot use a clandestine recording (hidden microphone, camera in common areas) to prove that your tenant is subletting without authorisation or making noise. Evidence obtained unfairly will be discarded by the judge. If you are in this situation, you must rely on lawful evidence: bailiff's report, witness statements, written exchanges.

For the tenant: If your landlord sets a trap (e.g., summons you to a bugged location to make you admit to damage), you can challenge the validity of his evidence. Invoke the principle of fairness and request the rejection of the unfair evidence. Concrete example: in Bordeaux, a tenant had his eviction annulled because the landlord had recorded a telephone conversation without informing him.

For the buyer or co-owner: In a neighbour dispute (abnormal disturbance), video taken from your window may be admissible if done openly and without intrusion. But if you install a hidden camera at the neighbour's, the evidence is unlawful. A figure: in 2023, the Bordeaux tribunal excluded evidence in 15% of cases for unfairness.

For the property professional: An estate agent who secretly records a conversation with a client to prove a verbal mandate risks having the evidence rejected. Better to have a written document or an email.

Four Tips to Avoid This Type of Dispute

• Always prefer written evidence: To prove an agreement, commitment or formal notice, use a durable medium (email, registered letter, bailiff's report). Avoid non-consensual audio or video recordings.
• Do not set traps: If you suspect a tenant of subletting, do not set an ambush, for example by offering to visit the flat under a false name. This could be deemed a stratagem.
• Use a bailiff to record evidence: For neighbour disturbances, damage, or inventory of fixtures, a bailiff is the professional authorised to collect lawful evidence. His report is valid until proven otherwise.
• Consult a lawyer before using questionable evidence: If you have a recording or photo whose lawfulness you question, seek advice before producing it in court. A lawyer will tell you whether it risks being excluded.
• Respect privacy: Any evidence obtained in violation of privacy (eavesdropping, video in a private place) is likely to be annulled. Never film in common areas without prior notice.

Further Reading: Related Case Law and Developments

This 2014 decision is part of a consistent line of the Court of Cassation. Already in 2011 (judgment No. 10-84.551), it had ruled inadmissible a police provocation to commit an offence. More recently, in 2019 (No. 18-86.891), it extended this principle to telephone interceptions ordered by a judge but implemented unfairly.

The trend is clear: judges are increasingly strict about the fairness of evidence, including in property matters. For example, the Bordeaux Court of Appeal in 2022 annulled a bailiff's report made without judicial authorisation in a private area. What this means for the future: evidence obtained by trickery or surprise will be increasingly difficult to admit. It is better to act transparently.

Summary and Next Steps

Checklist: What to do if faced with unfair evidence

1. Identify the stratagem: Was the evidence obtained by trickery, trap or violation of your privacy?
2. Preserve all elements: Keep the recordings, witness statements, dates and circumstances.
3. Consult a lawyer: A professional will assess the chances of having the evidence excluded.
4. Request rejection of the evidence: In proceedings, raise the inadmissibility on grounds of unfairness.
5. Produce lawful evidence: Compensate with written documents, bailiff's reports, witness statements.

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