Defensive Investigation
In Brazil, evidence is not a monopoly of the prosecution. The defense investigates too, under Federal Bar (CFOAB) Provimento No. 188/2018, which Gabriel Bulhões helped draft. This is a summary page in English — see the full Portuguese page for the complete legal analysis, FAQ and case examples.
Co-author of CFOAB Provimento No. 188/2018
Gabriel Bulhões helped draft Provimento No. 188/2018 of Brazil's Federal Bar Council (CFOAB), the rule that regulated defensive investigation nationwide. Someone who helped write the rule is better positioned to apply it in practice.
What is defensive investigation?
Defensive investigation is the set of fact-finding measures a defense attorney carries out to gather evidence and information useful to the defense, in parallel with — or independently of — the official investigation led by the police or public prosecutors.
The investigation is initiated by the defense attorney, not by the state. It can happen before, during, or outside any criminal proceeding. The result is evidence of the defense's own making — documents, expert reports, witness interviews and data analysis — that supports the defense's theory of the case in the court record.
The activity is regulated by OAB Provimento No. 188/2018, which sets out what a defense attorney may do, how each step must be documented, and its ethical limits. Gabriel Bulhões co-authored that rule and is the author of the Manual Prático de Investigação Defensiva (2nd ed.), the leading reference work on the subject in Brazil.
Why does defensive investigation exist?
Brazil's Federal Constitution guarantees full defense rights and adversarial process (art. 5, LV). Investigating is part of exercising those rights. Without its own investigation, the defense depends entirely on what the prosecution collects — which is not compatible with an adversarial system.
Full defense rights
The right to use all legitimate means of proof (Constitution, art. 5, LV). There is no full defense without the ability to produce one's own evidence.
Equality of arms
The defense cannot depend solely on what the prosecution gathers. Defensive investigation balances the evidentiary contest.
Adversarial system
Reinforced by the 2019 Anti-Crime Package (Law 13.964/2019) and the "garantias" judge model, Brazil's adversarial criminal system presumes both parties have their own investigative capacity.
How is it different from a police inquiry or a prosecutor's own investigation?
All three coexist in the Brazilian system, but differ in who conducts them, their goals and their limits.
| Aspect | Police Inquiry | Prosecutor's Own Investigation (PIC) | Defensive Investigation |
|---|---|---|---|
| Led by | Police chief (delegado) | Public prosecutor | Defense attorney |
| Goal | Establish authorship and materiality of the offense | Gather elements to support prosecution | Gather evidence favorable to the defense |
| Legal basis | Code of Criminal Procedure, arts. 4–23 | National Prosecutors Council Res. 181/2017 | OAB Provimento No. 188/2018; Constitution art. 5, LV |
| Evidence produced | Prosecution's evidence | Prosecution's evidence | Defense's evidence |
| Oversight | Judicial and prosecutorial oversight | Judicial oversight | Bar association oversight (ethics) |
What can the defense do in a defensive investigation?
OAB Provimento No. 188/2018 lists what a defense attorney may do — the scope is broader than most people assume.
- Interview witnesses. With the witness's consent, gather accounts and statements about the facts under investigation, properly documented.
- Obtain documents. Certificates, records and public or private data relevant to the defense's theory, subject to Brazilian data-protection law (LGPD).
- Retain expert examinations. Engineers, physicians, forensic accountants, digital forensics experts and other specialists can produce technical reports to be filed in the case record.
- Open-source research (OSINT). Collection and analysis of publicly available information — databases, public records, social media and other open sources — with specialized platforms such as Ethos Brasil.
- Site visits and on-site findings. In-person verification of facts and locations, with photographic records and documentation.
- Request further steps from the authorities. Under Code of Criminal Procedure art. 14, the defense can request that the police authority carry out specific steps, with the results added to the inquiry.
- Digital forensics. Collection and preservation of electronic evidence with demonstrable integrity, supported by specialized tools such as the Defenda-me platform.
What are the ethical limits of defensive investigation?
The strength of evidence depends on how it was obtained. Defensive investigation has clear limits, and respecting them is what guarantees the evidence's admissibility.
Consent
Witness interviews are voluntary. No investigative act may be carried out through coercion or undue pressure.
Lawfulness
Unlawfully violating privacy or confidentiality is prohibited. Evidence obtained by illegal means is inadmissible (Constitution art. 5, LVI) and can harm the defense.
No fabrication
Inducing false statements, staging facts, or destroying evidence is prohibited. Defensive investigation produces evidence — it does not manipulate it.
Attorney-client privilege
Information collected and the client's identity are protected by professional secrecy. The attorney's professional prerogatives shield the investigation.
Good faith and transparency
The attorney may not conceal their capacity when carrying out investigative acts. Transparency about who conducts each step is required by the Provimento.
Faithful documentation
Every act must be recorded faithfully. Documentation is what turns a fact-finding step into admissible evidence.
How is evidence gathered by the defense made to hold up in court?
Evidence produced by the defense can be filed and weighed by the judge. To do so, it needs two attributes: lawful collection and an unbroken chain of custody.
Integrity in collection
Evidence must be collected through the means provided for in the Provimento, without violating fundamental rights. The collection method is itself part of the chain of custody.
Chain of custody
A documented record of every step: collection, packaging, transport, storage and access — based on Code of Criminal Procedure arts. 158-A to 158-F, introduced by Law 13.964/2019.
Traceability
Every investigative act must be documented without gaps. Any break in the chain undermines the evidence's admissibility and probative value.
Admissibility
Evidence that is intact, lawfully obtained, and rigorously documented is evidence a judge will admit — and that carries real weight in the court's decision.